By Courtney Noll, PharmD Student
An individual’s blood glucose levels assist in controlling the secretions of two major regulatory hormones in the body: Insulin and glucagon. Insulin works to bring down levels of glucose in the blood when they have risen too high, and glucagon works to raise the blood glucose levels when they have fallen too low. A significant problem that many individuals are developing is the condition of insulin resistance. This issue is caused by obesity, sedentary lifestyles, poor eating habits, and genetics etc. This physiological condition occurs when cells fail to respond to the normal effects of insulin. In some cases insulin is created in less than sufficient quantities in the body, and in other cases, the human body fails to use the hormone effectively. As of now there is no specific medication approved by the Food & Drug Administration (FDA) for the treatment of insulin resistance, outside of diagnosis and treatment of diabetes, and the best form of conventional treatment is found to be weight loss and exercise. Smoking is also found to increase insulin resistance, and quitting the habit will contribute to an individual’s conventional treatment of the issue. Insulin resistance plays a significant role in the development of other serious medical conditions as well, including obesity, hypertension, type II diabetes, dyslipidemia (abnormal amount of lipids in the blood), and cardiovascular (heart) disease.1
A recent study was performed in order to evaluate the effects of weight loss on insulin resistance as well as other plasma and tissue markers of systemic and vascular inflammation. This was a prospective controlled study using 77 overweight and obese sedentary postmenopausal women. These women were split into 2 groups where 37 of the participants met 3 times a week and engaged in aerobic exercise and the remaining 40 participants did no aerobic exercising. This study used a state-of-the-art technique to measure insulin sensitivity, body composition, inflammatory biomarkers, and vascular adhesion molecules and carefully conducted weight loss and exercise regimes.2 In looking back at the results, evidence is shown that the markers that were measured and the level of insulin resistance was noticeably higher with a higher level of obesity.2 As the study progressed, it was also noticeable that with combined weight loss and aerobic exercise, the levels of insulin resistance and the other markers measured, also significantly decreased. Unfortunately, there were two limitations that came into play during this study. First of all, the study was done only in postmenopausal women and second, there was no nonintervention control group.2 By performing this study in exclusively postmenopausal women, the results cannot be applied accurately to different populations and/or groups of individuals.
This study may have had limitations, but it was not the only study showing the relationship between weight loss and reduced insulin resistance. In fact, there was no study that I found showing any opposing views or conflicting data. Another study showed the effects of weight loss on insulin resistance in adolescents and found that, weight loss at month 4 was associated with improved insulin sensitivity in obese adolescents.3 Another study published recently, was looking at the effects of weight loss, with and without exercise, on the measurements of blood pressure, blood glucose, and insulin resistance and found that: A reduction of 7% of the initial body weight, in overweight patients, improves systolic blood pressure, plasma glucose, and insulin resistance.4 Thirdly, another study found that using surrogate markers for insulin sensitivity, authors of the Diabetes Prevention Program showed that at one year, improvement in insulin sensitivity predicted lower risk for diabetes three years later.5
Study after study 6,7 shows the benefits of weight loss on various health measurements, but specifically focuses on insulin resistance. In my opinion, losing weight can be one of the most beneficial health choices an overweight individual can choose to accomplish. There are many rewarding diets and workout regimens that individuals have found to be successful. In addition, a gym membership and a simple 3 days per week attendance could be the start to a great beginning for any overweight individual. By decreasing their weight and, essentially decreasing insulin resistance, an individual will decrease their risk of hypertension, type 2 diabetes, dyslipidemia, and cardiovascular disease. With the positive effects of losing weight on insulin resistance, what is weight loss worth to you?
- Reviews CT. Studyguide for Principles of Anatomy and Physiology by Gerard J. Tortora, Isbn 9780470565100. Academic Internet Publishers; 2012.
- Ryan A, Ge S, Blumenthal J, Serra M, Prior S, Goldberg A. Aerobic Exercise and Weight Loss Reduce Vascular Markers of Inflammation and Improve Insulin Sensitivity in Obese Women. Journal Of The American Geriatrics Society [serial online]. April 2014;62(4):607-614. Available from: CINAHL Plus with Full Text, Ipswich, MA. Accessed September 23, 2014.
- Abrams P, Levitt Katz L, Berkowitz R, et al. Threshold for improvement in insulin sensitivity with adolescent weight loss. Journal Of Pediatrics [serial online]. September 2013;163(3):785-790. Available from: CINAHL Plus with Full Text, Ipswich, MA. Accessed September 23, 2014.
- Trussardi Fayh A, Lopes A, Fernandes P, Reischak-Oliveira A, Friedman R. Impact of weight loss with or without exercise on abdominal fat and insulin resistance in obese individuals: a randomised clinical trial. British Journal Of Nutrition [serial online]. August 28, 2013;110(3):486-492. Available from: CINAHL Plus with Full Text, Ipswich, MA. Accessed September 23, 2014.
- McLaughlin T, Schweitzer P, Reaven G, et al. Persistence of improvement in insulin sensitivity following a dietary weight loss programme. Diabetes, Obesity & Metabolism [serial online]. December 2008;10(12):1186-1194. Available from: MEDLINE with Full Text, Ipswich, MA. Accessed September 24, 2014.
- Ling Chun K, Wuillemin P, Rizkalla S, et al. Insulin resistance and inflammation predict kinetic body weight changes in response to dietary weight loss and maintenance in overweight and obese subjects by using a Bayesian network approach. American Journal Of Clinical Nutrition [serial online]. December 2013;98(6):1385-1394. Available from: CINAHL Plus with Full Text, Ipswich, MA. Accessed September 23, 2014.
- Calleja Fernández A, Vidal Casariego A, Cano Rodríguez I, Ballesteros Pomar M. One-year effectiveness of two hypocaloric diets with different protein/carbohydrate ratios in weight loss and insulin resistance. Nutricion Hospitalaria [serial online]. December 2012;27(6):2093-2101. Available from: CINAHL Plus with Full Text, Ipswich, MA. Accessed September 23, 2014.