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Diabetes, Insulin Resistance, Belly Fat Gain in HIV
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Increased Fat Gain in Belly Found in Patients With Lipodystrophy
The preliminary FRAM study findings reported by Carl Grunfeld at Barcelona were that increased belly fat was not necessarily associated with the syndrome we call lipodystrophy. But in a separate and smaller study Don Kotler found differently and it's is discussed just below. Granted these are 2 different studies, conducted differently and with different patients. But the different findings by Kotler are I think worth note. Similarly, in a second small cross-sectional study in 56 HIV+ individuals with self-reported lipodystrophy reported at Barcelona, HIV+ patients had more visceral belly fat than HIV negative individuals. HIV negative individuals had less subcutaneous fat. Objective testing was performed: MRIs and fat aspirations of subcutaneous abdominal tissue.
To enter a multi-center trial of growth hormone (Serostim) in HARS (HIV-associated body changes), HIV patients were required to have increased waist circumference (WC) and waist-hip ratios (WHR). Data from first 53 HARS patients (24.5% female) who met eligibility criteria were compared to that of healthy men (n= 85) and women (n=96) of similar age and height from a database of whole-body MRI scans from St. Luke's-Roosevelt Hospital Center in New York, NY.
Compared to control patients (healthy men and women), HARS patients did not differ significantly in weight, body mass index, or hip circumferences. However, HARS men and women had significantly greater chest circumferences, WC, WHR, and VAT than healthy individuals (all p < 0.0007). Mean VAT (visceral belly fat) in the current study subjects was more than 4 times higher than in healthy adult controls, as well as about twice the average reported in FRAM.
Are Diabetes and Insulin Resistance Different In HIV-infected Individuals Than HIV Negative
In the following studies the authors found that insulin resistance and diabetes may be different in HIV-infected persons. They found weight and fat loss by diet and exercise may not improve insulin resistance and diabetes in HIV-infected individuals. But the study looked only at obese African-American and Hispanic women.
15 clinically stable obese HIV+ women of an intended 30 have completed an intense 12-week diet and exercise program consisting of 3 times weekly supervised exercise programs at St Luke's-Roosevelt Hospital in New York City under the supervision of Ellen Engelson and Don Kotler. The diet is 1200 kcal, 50% carbohydrate, 30% fat and 20% protein. The exercise is a combined aerobic and resistance program. Patients receive nutrition education. Before and after the intervention, body composition is measured by anthropometry, dual energy x-ray absorptiometry (DXA) and whole body magnetic resonance imaging (MRI). Metabolic measurements, completed in 5 women, include fasting glucose and insulin, and insulin sensitivity (SI) by frequently sampled intravenous glucose tolerance test.
The 15 women who have completed the study show an average weight loss of about 14 pounds. Presumably these women were mostly African-American and Hispanic. With a combined low calorie diet and exercise program, significant loss of lean tissue including skeletal muscle may be prevented during intentional weight loss in obese HIV+ women. Almost all of the weight lost was fat, so the exercise program successfully preserved skeletal muscle mass. Subcutaneous fat and visceral fat in the belly significantly declined. Caution is advised that weight loss can also reduce fat in face and other peripheral areas: arms, legs, etc. However, despite the loss of weight, body fat, and SAT, insulin resistance changed little. Insulin resistance can be improved with diet, exercise, and reduced fat in HIV-negative individuals. Kotler and Engelson conclude that significant loss of total weight and visceral fat, and reduction in waist circumference, all associated with greater insulin resistance and cardiovascular disease, may not improve insulin sensitivity in the context of HIV disease and treatment. But, I'm not sure I agree completely with this conclusion. I think it depends on the cause of the insulin resistance or diabetes. If the diabetes or insulin resistance is caused by an underlying genetic predisposition or a cause other than HIV or ART, perhaps insulin resistance and diabetes can be improved. Additionally, the gender and ethnicity of the study participants may have influenced the results of the study. We need additional larger studies which can explore this question better.
In a substudy of these patients, Jeanine Albu found insulin resistance and increased fasting insulin are not related to increased fat mass in obese HIV+ women. Furthermore, it is unclear if fat loss will improve insulin sensitivity in these women. Fasting insulin increased and insulin sensitivity decreased with increased fat (and SAT) in HIV- women, while fasting insulin increased and insulin sensitivity decreased with decreased fat (and SAT) in HIV+ women. In other words, insulin sensitivity did not increase in the women who completed the weight loss program despite significant fat loss. But, glucose was normal in the women before starting the diet and exercise program (106 mg/dL). Insulin was 33 um/mL. Insulin sensitivity was 0.7. Perhaps improvements would habe been seen if glucose was highly elevated above normal. In addition, the type of diet the patients followed can be important. The
percentage of fats, sugar, and carbohydrates are very relevant to sugar
management.
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