Exercise and Statins: Revisited

Exercise and statins 

I chronicled someone with type 1 diabetes whose ability to exercise was compromised by his use of statins. Statins are medications prescribed to lower cholesterol levels or abnormal levels of blood fats, given to lower your risk of heart attack and stroke. Examples include Altoprev, Crestor, Lescol, Lipitor, Livalo, Mevacor, Pravachol, and Zocor.

The updated cholesterol guidelines have led to even more adults with diabetes and prediabetes being put on these medications. For anyone unwilling or unable to change diet and lifestyles sufficiently or with genetically high levels of blood lipids, the experts have claimed that the benefits of statins likely greatly exceed the risks. If those risks include the risk of becoming more inactive, then I vehemently disagree with this claim.

This issue is resurfacing for discussion because of a recent study in JAMA Internal Medicine online. That study examined statin treatment among adults aged 65 to 74 years and 75 years and older when used to prevent heart attacks. The statin in in the study was pravastatin (Pravachol), and the adults already had elevated LDL levels and hypertension in most cases. Interestingly, over a six-year period, taking that statin did not lower the risk of having a coronary heart disease event compared to usual care in these older individuals (some of whom likely had diabetes or prediabetes, although this was not stated).

So, if statins don’t always prevent coronary events and may keep you from being active and naturally lowering your cardiovascular risk with physical activity, why take them at all? It may be that glucose, blood pressure, and cholesterol all need to be aggressively managed to see benefits, but then why not try to do that with exercise and physical activity (which can lower all three)? As I stated before, likely the greatest risk factor for heart disease is physical inactivity, so prescribing statins that make people sedentary is counterproductive. At least have them try another medication to see if it has a lesser negative impact on being active.

We already know that many statins increase the risk of developing type 2 diabetes. A recent meta-analysis of 20 studies just reported an increased risk of new-onset diabetes from 9% to 13% associated with statins in just one year, and this could be an underestimation of the risk of developing type 2 diabetes due to statins. Diabetes is known to be a strong and independent risk factor by itself for cardiovascular disease. Does this make the “cure” for high LDL-cholesterol worse than the condition itself?

As a group of medications, statins are recognized for frequently causing muscle and joint issues. Muscular effects from statin use, such as unexplained muscle pain and weakness, are common and may result from a compromised ability to generate energy. The occurrence of muscular conditions like myalgia, mild myositis, severe myositis, and rhabdomyolysis, although relatively rare, is doubled by diabetes. Others have an increased susceptibility to exercise-induced muscle injury when taking statins. Other symptoms, such as muscle cramps during or after exercise, nocturnal cramping, and general fatigue, generally resolve when people stop taking them. It is also concerning that long-term use of statins negatively impacts the organization of collagen and decreases the biomechanical strength of the tendons, making them more predisposed to ruptures. Statin users experience more spontaneous ruptures of both their biceps and Achilles tendons.

You should talk with your doctors about whether it may be possible to manage your heart disease risk without taking statins long-term for this reason. If you experience any of these symptoms, bring up possibly switching to another cholesterol-lowering drug. A newer one on the market that is not a statin is Repatha and is worth a look if such medications absolutely have to be taken. Instead of blocking LDL production by the liver, Repatha apparently is an injectable antibody that helps the liver clear bad LDL-cholesterol from your blood. While its musculoskeletal effects remain to be determined (if any), it appears that it is unlikely to do more harm than statins. It’s worth considering…

When Do You Need a Checkup First Before Starting Exercise?

BP checkHow do you know if you need to get a checkup or medical clearance before you start any exercise training? You should have regular checkups at least annually with your doctor or another healthcare provider if you have any type of diabetes. This helps you keep on top of any problems that may pop up over time that have nothing to do with being physically active.

However, you probably don’t need to see a doctor before you start doing easy workouts or moderate activities like brisk walking. Requiring anyone with diabetes to get medical clearance before starting any type or intensity of exercise is recommended by the American College of Sports Medicine, but is not recommended by the American Diabetes Association because it sets too big of a barrier to participating in regular activities.

On the other hand, having a checkup before you begin more vigorous workouts is a good idea. It also depends on your age, your general health, and your physical activity level. If you’re already doing intense exercise, it’s not necessary, but it is advised for almost everyone with diabetes who is not already exercising at that level—just to be safe.

If/when you do have a checkup, get your blood pressure, heart rate, and body weight measured. If your doctor recommends that you do an exercise stress test, you’ll have to do walking on a treadmill or riding a stationary bike for around ten minutes. Your checkup may also include lab tests (urinalysis, kidney function testing, serum lipid evaluation, and electrolyte analysis) and screening for any diabetes-related complications (including heart, nerve, eye, and kidney disease). Most complications will not keep you from being active, but you may need to take precautions to exercise safely and effectively in certain cases.

For most people, getting a diagnostic graded exercise test is really going too far. Having one is only recommended by the American Diabetes Association if you’re over 40 and have diabetes; or if you’re over 30, have had diabetes for 10 or more years, smoke, have high blood pressure, have high cholesterol, or have eye or kidney problems related to diabetes. If you’re planning to do vigorous training that gets your heart rate up high, these criteria are relevant. If you’re just planning on doing mild or moderate aerobic activity or resistance training, such extensive (and often expensive) testing is unnecessary if you’re reasonably healthy or already fit and don’t have any symptoms of heart or vessel disease.

If you have any pre-existing health complications, you may need to take extra care to prevent problems during exercise. If your blood glucose has been in check, you’ve already been physically active, and you don’t have any serious diabetic complications, then go ahead and keep doing what you’re doing. If you’re very active, getting an extra checkup before you replace your current exercise regime with another exercise routine is neither necessary nor advised.

You still may need to take certain precautions when you exercise, particularly related to getting low blood glucose during and following the activity, going too high, and getting dehydrated. If you have any concerns, check with your healthcare provider at your next visit to discuss any precautions that may be important for your unique health circumstances when exercising.

Resistance Training When You’re Older or Have Limited Mobility

In addition to aerobic activities, you can greatly improve your blood glucose by doing some resistance, or weight, training. Like so many systems in the body, if you don’t use all your muscle fibers, you lose them over time. Anyone past the age of 25 is slowly losing muscle mass, which decreases how many carbs you can store in your muscles as glycogen. You need to retain as much of your muscle mass as possible—and gain more muscle if you can.

If you’re older or have physical limitations, working on your muscular strength helps prevent loss of muscle mass and bone density. The goal of resistance training is increased muscular fitness, both strength and endurance. Regardless of what you type you choose, engaging in any resistance training is always better than doing none.

What should you do if you’re just starting out? Choose among using resistance bands, free weights, resistance machines, or body weight as resistance (for example, doing planks or lunges). The main difference is the intensity of training. For each workout, try to do at least eight to 10 different resistance exercises (at least six to start) that work your full musculature (upper body, lower body, and core). If nothing else, start with strength training exercises that use your own body weight as resistance (like planks, lunges, or wall or modified knee push-ups). Resistance bands, dumbbells, and household items used as resistance (e.g., full water bottles and soup cans) also all work to do these exercises at home on your own. Most training can be done seated for those with mobility and balance issues.

How often should you train? You should ideally perform resistance training at least 2 nonconsecutive days each week, preferably 3. Working the same muscle groups daily doesn’t allow adequate time for recovery and muscle repair between workouts, but if you want to resistance train more than 3 days per week, you can alternate muscle groups when you train on consecutive days. Doing it as infrequently as one day a week can still be beneficial for muscle mass and insulin action.

How hard should it feel? You can gain or maintain strength by doing anywhere from 3 to 15 repetitions per set on each exercise and 1 to 3 sets, with rest between multiple sets. Generally, working up to doing 8 to 12 repetitions and two to three sets is recommended, although you can get stronger from just doing a single set. Start with an easier weight and more reps, and gradually work up to more resistance and fewer reps. If you have joint limitations or other health complications, complete 1 set of exercises for all major muscle groups, starting with 10 to 15 repetitions and progressing to 15 to 20 repetitions before adding extra sets. Your muscles should be working hard during the last 3 to 4 reps in each set, regardless. If it feels too easy, try a heavier resistance or weight; if you can’t complete your goal number of repetitions, try using a lighter amount.

What else do you need to do? Make sure to warm up your muscles and joints before starting resistance training. The best way to warm up if not also doing an aerobic workout is to go through the same motions that used for the workout, but without any resistance. Take time to have them stretch any muscles that feel tight during workouts, since that will help with increasing both flexibility and strength.

How can you avoid getting injured? To avoid injury or work around your existing joint limitations, progress slowly toward working out harder or more frequently. It’s generally better to increase your weight or resistance first—only the number of reps you’re doing is way too easy—and only then increase your number of sets and lastly add in additional training days. Expect that is should take you six months or more to progress up to doing 3 days per week (and only if you want to) and doing up to 3 set of 8 to 10 reps each—an optimal goal for most adults with diabetes.

Resistance Training Goals, Recommendations, and Precautions:

  • Short-term goal: 1 to 2 times per week, 6 to 8 exercises to start
  • Long-term goal: 3 days per week, 10 to 12 exercises
  • 2 to 3 sets per exercise
  • 10 to 15 reps per exercise to start; 8 to 12 reps per exercise later on
  • Start slowly with training and build up
  • Don’t resistance train the same muscle groups more often than every other day
  • Gradually increase resistance or weights over time
  • Perform exercises with slow controlled movements
  • Extend limbs and use the full range of motion around each joint being worked
  • Breathe out during exertion, and always avoid breath holding
  • Stop exercise if dizziness, unusual shortness of breath, chest discomfort, palpitations, or joint pain occurs

Finding Fitness Professionals Trained in Diabetes–It’s Hard!

Personal training 3One in three Americans has diabetes or prediabetes. You would think that finding a fitness professional—a personal trainer, physical therapist, or other allied fitness and health trainer—that knows enough about diabetes to be helpful wouldn’t be that hard, right? Think again.

Why does it matter whether your trainer knows about diabetes? Well, if you had severe arthritis in your knees, you’d want a trainer who knows enough to avoid making you do certain activities that might be injury-inducing (burpees come to mind). The same goes if you have diabetes. Over the years, I have just heard of too many trainers ending up getting their clients injured because they didn’t understand that diabetes makes people more prone to overuse injuries, or that certain medications increase the risk for activity-associated hypoglycemia, or that most people with type 2 diabetes who are overweight and sedentary are going to be demotivated or injured by being forced to train like they do on “The Biggest Loser” (even though trainers shouting at people makes for good reality TV).

Many professional fitness organizations certify trainers and other fitness professionals, including the American College of Sports Medicine (ACSM), American Council on Exercise (ACE), National Academy of Sports Medicine (NASM), Athletics and Fitness Association of America (AFAA), International Sports Sciences Association (ISSA), and at least 30 other groups that offer certifications for personal trainers, health coaches, and other allied professions. The certification requirements vary widely by organization, however, and most (but not all) require continuing education to maintain the certification. Some offer full training courses, while others barely meet minimal standards. The premier certifying organizations are ACSM and ACE at present.

One problem is that it’s not easy to identity certified fitness professionals who are knowledgeable about working with people with diabetes (all types and ages). What’s more, very few diabetes training programs are available for fitness professionals, and most trainers are more interested in learning more about training techniques that they can use in their prescribed workouts than chronic diseases. I personally have been on a crusade for the past two years trying to offer expert training for fitness professionals about working with diabetic clients. I finally got a program done for ACSM online as of February 2017 and will shortly have programs offered through ACE and others as well (check on Diabetes Motion Academy for these and other programs).

One bright note is the Medical Fitness Network (MFN), a free online resource directory for consumers to locate fitness and allied healthcare professionals who have a background in and provide services for those with chronic disease, medical conditions, disabilities and women’s health issues. MFN donates its service as a database management company to the top medical and health organizations who do not offer resources for locating these professionals. Fitness and healthcare professionals can join to increase their online exposure and credibility for a modest annual fee. It is my hope that some of the larger fitness organizations (like ACSM) will also soon see the value of making diabetes-savvy fitness professionals easier for consumers to find—for the benefit of everyone!

Staying Active with Aging Joints and Diabetes

Using bandsWithout properly functioning joints, our bodies would be unable to bend, flex, or even move. A joint is wherever two bones come together, held in place by tendons that cross the joint and attach muscles to a bone on the other side and ligaments that attach to bones on both sides of the joint to stabilize it. The ends of the bones are covered with cartilage, a white substance. Specialized cells there called chondrocytes produce large amounts of an extracellular matrix composed of collagen fibers, proteoglycan, elastin fibers, and water. Tendons and ligaments are also made up of primarily of collagen.

Joints can be damaged, however, making movement more difficult or painful. Joint cartilage can be damaged by acute injuries (i.e., ankle sprain, tendon or ligament tears) or overuse (related to repetition of joint movements and wear-and-tear over time). Damage to the thin cartilage layer covering the ends of the bones is not repaired by the body easily or well, mainly because cartilage lacks its own blood supply.

Aging alone can cause you to lose some loss of this articular cartilage layer in knee, hip, and other joints—leading to osteoarthritis and joint pain—but having diabetes also potentially speeds up damage to joints. Although everyone gets stiffer joints with aging, diabetes accelerates the usual loss of flexibility by changing the structure of collagen in the joints, tendons, and ligaments. In short, glucose “sticking” to joint surfaces and collagen makes people with diabetes more prone to overuse injuries like tendinitis and frozen shoulder (1; 2). It may also take longer for their joint injuries to heal properly, especially if blood glucose levels are not managed effectively. What’s more, having reduced motion around joints increases the likelihood of injuries, falls, and self-imposed physical inactivity due to fear of falling.

Reduced flexibility limits movement around joints, increases the likelihood of orthopedic injuries, and presents a greater risk of joint-related problems often associated with diabetes, such as diabetic frozen shoulder, tendinitis, trigger finger, and carpal tunnel syndrome. These joint issues can come on with no warning and for no apparent reason, even if an individual exercises regularly and moderately, and they may recur more easily as well (3). It is not always just due to diabetes, though, since older adults without diabetes experience inflamed joints more readily than when they were younger.

So what can you do to keep your joints mobile if you’re aging (as we all are) and have diabetes? Regular stretching to keep full motion around joints can help prevent some of these problems, and also include specific resistance exercises that strengthen the muscles surrounding affected joints. Vary activities to stress joints differently each day. Overuse injuries occur following excessive use the same joints and muscle in a similar way over an extended period of weeks or months, or they can result from doing too much too soon.

Doing moderate aerobic activity that is weight-bearing (like walking) will actually improve arthritis pain in hips and knees (4). People can also try non-weight-bearing activities, such as aquatic activities that allow joints to be moved more fluidly. Swimming and aquatic classes (like water aerobics) in either shallow or deep water are both appropriate and challenging activities to improve joint mobility, overall strength, and aerobic fitness. Walking in a pool (with or without a flotation belt around the waist), recumbent stationary cycling, upper-body exercises, seated aerobic workouts, and resistance activities will give you additional options to try.

Finally, managing blood glucose levels effectively is also important to limit changed to collagen structures related to hyperglycemia. Losing excess weight and keeping body weight lower will decrease the risk for excessive stress on joints that can lead to lower body joint osteoarthritis (5). Simply staying as active as possible is also critical to allowing your joints to age well, but remember to rest inflamed joints properly to give them a chance to heal properly. You may have to try some new activities as you age to work around your joint limitations, but a side benefit is that you may find some of them to be enjoyable!

References:

  1. Abate M, Schiavone C, Pelotti P, Salini V: Limited joint mobility in diabetes and ageing: Recent advances in pathogenesis and therapy. Int J Immunopathol Pharmacol 2011;23:997-1003
  2. Ranger TA, Wong AM, Cook JL, Gaida JE: Is there an association between tendinopathy and diabetes mellitus? A systematic review with meta-analysis. Br J Sports Med 2015;
  3. Rozental TD, Zurakowski D, Blazar PE: Trigger finger: Prognostic indicators of recurrence following corticosteroid injection. J Bone Joint Surg Am 2008;90:1665-1672
  4. Rogers LQ, Macera CA, Hootman JM, Ainsworth BE, Blairi SN: The association between joint stress from physical activity and self-reported osteoarthritis: An analysis of the Cooper Clinic data. Osteoarthritis Cartilage 2002;10:617-622
  5. Magrans-Courtney T, Wilborn C, Rasmussen C, Ferreira M, Greenwood L, Campbell B, Kerksick CM, Nassar E, Li R, Iosia M, Cooke M, Dugan K, Willoughby D, Soliah L, Kreider RB: Effects of diet type and supplementation of glucosamine, chondroitin, and msm on body composition, functional status, and markers of health in women with knee osteoarthritis initiating a resistance-based exercise and weight loss program. J Int Soc Sports Nutr 2011;8:8

Exercise Management in Type 1 Diabetes: A Consensus Statement

JDRF Consensus Statement Cover

Above you see part of the first page of a new consensus statement that comes from many of the individuals involved with the creation and launch of the new JDRF PEAK Performance Program, aimed at educating both clinicians and people with type 1 diabetes how to manage the complexities of being active. In my opinion, this recently published consensus statement on exercise and type 1 diabetes is long overdue and much needed. I managed to get the American Diabetes Association to let me chair an updated position statement (see my November blog) and include type 1 diabetes in it but, unfortunately, never just one addressing type 1 and exercise alone so this JDRF one fills a huge void.

The past decade has seen a growing number of publications related to diabetes management during exercise in people who have to either inject or pump insulin to stay alive. As you well know, whether insulin is injected or pumped, it is not being delivered where it normally ends up in a body that can release its own insulin, and this altered insulin delivery leads to alterations in hormones and blood glucose management by the liver. Normally, your liver would be able to either release or store glucose to keep your levels constant, but not without these proper hormonal signals.

Consequently, the only way you can keep your blood glucose levels normal (or near normal) with exercise is to take in carbohydrate/food, lower circulating insulin levels, or both during activities. Given that exercise is a huge stressor to normal metabolic control of blood glucose, it can make your diabetes more difficult to manage–even though exercising is generally beneficial for a number of other health reasons. This new consensus statement does an excellent job of covering all of the potential effects of engaging in differing physical activities, along with comprehensive management strategies involving changes in food intake and adjustments in basal and/or bolus insulin dosing. It also points out the many areas that need additional (or even any) research with regard to exercising with type 1 diabetes, either to enhance health or sports performance. Read it now if you haven’t already for some great advice!

Reference:

(1) Riddell MC, Gallen IW, Smart CE, Taplin CE, Adolfsson P, Lumb AN, Kowalski A, Rabasa-Lhoret R, McCrimmon RJ, Hume C, Annan F, Fournier PA, Graham C, Bode B, Galassetti P, Jones TW, Millán IS, Heise T, Peters AL, Petz A, Laffel LM. Exercise management in type 1 diabetes: a consensus statement, Lancet Diabetes Endocrinol. 2017 Jan 23. pii: S2213-8587(17)30014-1. doi: 10.1016/S2213-8587(17)30014-1. [Epub ahead of print]

 

 

Losing Weight with Diabetes: What Prevents It and Causes Weight Gain

Scale weight 2Last year I was included in a discussion on a Facebook group for athletes with diabetes about how hard it can be to lose weight through exercise. While I don’t have all the answers on this topic, here are some ideas about what can make you gain weight or keep you from losing weight with diabetes, based on my decades of professional and personal experience with diabetes and weight management, and what you can do about it.

Insulin: My former graduate student with type 1 diabetes went on an insulin pump and promptly gained about 10 pounds, even though his blood glucose control improved only marginally. Why does it happen to so many insulin users? As an anabolic hormone, insulin promotes the uptake and storage of glucose, amino acids, and fat into insulin-sensitive cells around your body (mainly muscle and fat cells). It doesn’t matter whether it’s released naturally, injected, or pumped. Going on insulin therapy is associated with fat weight gain (1), for people with both type 1 and type 2 diabetes. When you lower blood glucose with insulin, you keep and store all of the calories instead of losing some glucose through urine (during hyperglycemia). Unfortunately, some people skip or limit their insulin use to help them lose weight (2), but that is a dangerous practice that can lead to loss of excess muscle mass and life-threatening conditions like DKA. The best way to balance your insulin use and your body weight, in my opinion, is to be physically active to keep your overall insulin levels lower. It’s easier to lose weight, too, when you’re taking less insulin—or releasing less of your own if your pancreas still does that.

Food Choices: What you choose to eat has a huge impact on your insulin needs as well as your body weight. My graduate student found that by doing frequent dosing with his insulin pump, he was eating more overall because he could without having to take another injection with a needle. Just because insulin use can make it easier for you to eat cake and other formerly “forbidden” foods doesn’t mean that you need to eat them! There are advocates out there for all sorts of diets for people with diabetes, including ultra-low-carb ones (like Dr. Bernstein’s), vegan ones, etc. Personally, what I have always founds works best is a balanced diet. People don’t necessarily lose weight on low-carb diets, even though their insulin requirements are lower because fat is so much denser in calories (at over 9 calories/gram of fat) than carbs or protein (both 4 calories per gram). If you cut carbs out of your diet, you have to eat something in its place. It’s just too easy to overdose on fat calories without realizing it, and even when your muscles become insulin resistant for any reason, insulin still works to put fat into storage depots around the body. Don’t completely avoid carbs; rather, choose them wisely—eating more carbs that are absorbed more slowly and don’t cause spikes in blood glucose that you have to try to match with large doses of insulin that often lead to hypoglycemia later. Most carbs are fully absorbed in the first hour or two after you eat them, and even rapid-acting insulin can linger for up to 8 hours afterwards. Besides, insulin requirements are determined by more than just carbs, and eating fat with the same number of carbs increases insulin requirements (3). It’s not just about carb counting anymore (and never has been for me); it’s about picking the right balance and type of carbs, as well as total amounts of protein (good for preventing lows 3 to 4 hours later) and fat (fully absorbed in 5 to 6 hours, causing insulin resistance).

Treating Lows: I was contacted once by a US Olympic team handball player with type 1 diabetes who wanted to ask me why she was gaining fat weight while doing all her training. My first question to her was, “Are you treating a lot of lows?” I knew she was going to answer yes. Gaining weight from treating lows is common in people using insulin, whether they are active or not. One of the biggest deterrents to successful weight loss and prevention of weight gain with diabetes is being forced to treat frequent bouts of hypoglycemia with glucose, sugary drinks, or food. Even though these calories are necessary to treat a medical condition, they still count as calories in the body. One way to cut back on lows is to decrease your insulin intake to prevent them, which may include decreasing meal-time insulin doses before exercise, insulin taken for food after exercise, and basal insulin doses to prevent later-onset hypoglycemia following activities. It also helps to more precisely treat lows instead of overtreating them (it’s harder to follow this advice when you’re low, though!) Immediately treat lows first with glucose—in the form of tablets, gels, or candy containing dextrose like Smarties—and then reassess later if you need additional food intake (often a mix of carbs, protein, and fat) to fully correct the low and prevent lows later on. Juice, although often touted as a treatment for hypoglycemia, contains fructose (fruit sugar) that is much, much more slowly absorbed than glucose and can lead to overtreating lows while you’re waiting for the juice to kick in. Don’t eat more calories treating a low than you need to!

Lack of Physical Movement: Finally, and I probably should have listed this section first, expending more calories can help prevent weight gain, even if you take insulin. In adults with type 1 diabetes, having an active lifestyle compared with a more sedentary one has been associated with a lower BMI (body mass index) and percentage of total and truncal fat mass (5). The more you move, the less insulin your body needs to get the same glucose-lowering effect. Requiring smaller doses of insulin allows you to 1) treat lows with fewer calories overall, and 2) avoid having as many lows from being off on your dosing. In anyone who is insulin resistant (most people with type 2 diabetes and many with type 1 who are inactive), total insulin requirements will be so much higher that there is a lot more room for error. Injected or pumped insulin is generally absorbed at a speed dictated by the dose, meaning that larger doses take longer to fully absorb and the insulin “tail” hangs around for longer. Taking or releasing less insulin due to being physically active means that all of the carbs you take will be stored as carbs in muscle or liver and not converted into fat to be stored. Stay regularly active—even if that means just standing up more or taking more daily steps–to keep your calorie expenditure high and your insulin needs low.

References:

(1) Conway B, Miller RG, Costacou T, Fried L, Kelsey S, Evans RW, and Orchard TJ. Temporal patterns in overweight and obesity in Type 1 diabetes. Diabet Med 27: 398-404, 2010. (http://www.ncbi.nlm.nih.gov/pubmed/20536510)

(2) Ackard DM, Vik N, Neumark-Sztainer D, Schmitz KH, Hannan P, and Jacobs DR, Jr. Disordered eating and body dissatisfaction in adolescents with type 1 diabetes and a population-based comparison sample: comparative prevalence and clinical implications. Pediatr Diabetes 9: 312-319, 2008. (http://www.ncbi.nlm.nih.gov/pubmed/18466215)

(3) Wolpert HA, Atakov-Castillo A, Smith SA, and Steil GM. Dietary Fat Acutely Increases Glucose Concentrations and Insulin Requirements in Patients With Type 1 Diabetes: Implications for carbohydrate-based bolus dose calculation and intensive diabetes management. Diabetes care 36: 810-816, 2013. (http://www.ncbi.nlm.nih.gov/pubmed/23193216)

(4) Brown RJ, Wijewickrama RC, Harlan DM, and Rother KI. Uncoupling intensive insulin therapy from weight gain and hypoglycemia in type 1 diabetes. Diabetes Technol Ther 13: 457-460, 2011. (http://www.ncbi.nlm.nih.gov/pubmed/21355723)

(5) Brazeau AS, Leroux C, Mircescu H, and Rabasa-Lhoret R. Physical activity level and body composition among adults with type 1 diabetes. Diabet Med 29: e402-408, 2012. doi: 410.1111/j.1464-5491.2012.03757.x. (http://www.ncbi.nlm.nih.gov/pubmed/22817453)