Lifestyle Modification and Metformin Use in the Treatment of HIV

Overview

A healthy diet and exercise have improved the health of people without human immunodeficiency virus (HIV) who have Metabolic Syndrome. In this study we would like to find out if the same benefit can be seen in people with HIV and Metabolic Syndrome. Patients with Metabolic Syndrome usually have a large waist, high blood cholesterol levels, high blood pressure, and high blood sugar levels. These are risk factors, which may increase one's chance of developing heart disease and/or diabetes. The purpose of the study is to evaluate the effects of different methods of treating HIV associated Metabolic Syndrome. The groups are: 1) a lifestyle modification program plus metformin (also known as glucophage), 2) lifestyle modification plus placebo, 3) metformin alone or 4) placebo alone. The lifestyle modification program consists of nutrition and exercise sessions with the goal of improving body composition, heart health, and ways to lower the risk of developing diabetes.

After two initial screening visits with medical and nutrition staff for informed consent and determination of eligibility qualifying subjects will be seen for a baseline visit. At baseline subjects will have an interval history and physical exam, lipodystrophy evaluation by investigator and patient report. Bloods will be taken for insulin, glucose, HgbA1c, lipid studies, creatinine, liver function, serum lactate, urine pregnancy (women), CD4, viral load, and complete blood count (CBC). Metabolic assessment will include a 2-hour oral glucose tolerance test and indirect calorimetry. Carotid ultrasound will be done for assessment of intima-media thickness. Body composition will be assessed by dual energy x-ray absorptiometry (DEXA), single-slice magnetic resonance imaging (MRI) scanning through the abdomen and mid thigh, magnetic resonance spectroscopy scanning to assess intramyocellular lipid of the calf, anthropometric measurements, and Cardiac computed tomography (CT) will be done. After the baseline visit, subjects will be randomized to 1 of 4 groups: 1) a lifestyle modification program plus metformin (also known as glucophage), 2) lifestyle modification plus placebo, 3) metformin alone or 4) placebo alone. The starting dose of metformin will be 500mg twice daily and this will increase to 850mg twice daily at the 3-month visit. An identical visit to that at baseline will be repeated at 12-months. Subjects will return at 1 month for an interval history and physical exam, assessment of compliance and side effects. Blood will be collected for CBC, lactate, liver function, and creatinine. Women will have a urine pregnancy. A 6-month visit will include an interval history and physical exam, assessment of compliance and side effects, 2 hour oral glucose tolerance test, fasting bloods (glucose, lipid panel, creatinine, liver function, serum lactate, CBC) will be done, a urine pregnancy will be checked in women. Carotid ultrasound will be done and body composition will be assessed by anthropometric measurements and DEXA scan. There will also be a short visit at 3 and 9 months to obtain an interval history and physical exam, safety labs (serum lactate, CBC, liver function, and creatinine), urine pregnancy (women). Subjects randomized to metformin or placebo will increase their dose from 500mg twice daily to 850mg twice daily at the 3 month visit. At each of the visits review of a 4 day food record will occur. Those randomized to lifestyle modification will attend weekly sessions with a study investigator to cover a "core-curriculum" that is modeled after the Diabetes Prevention Program (DPP) intervention. The primary goals of the lifestyle modification program are derived from a combination of recommendations from the American Academy of Clinical Endocrinologists (AACE) and National Cholesterol Education Program (NCEP). The goals are to eat less than or equal to 35% of total calories from fat (less than 7% from saturated fat, up to 10% from polyunsaturated fat with emphasis on sources of omega 3 fatty acids and reduction of trans fatty acids, up to 20% from monounsaturated fats), and 25-35g of fiber per day. The intensity of the counseling sessions will decrease in months 10 through 12 to biweekly counseling session with study investigators and biweekly phone contact, alternating. In addition to the program outlined above, those randomized to the lifestyle modification group will also participate in progressive resistance training. Each training session will begin with a 5 minute warm-up on a stationary bicycle at 50% of the estimated maximal heart rate (maximal heart rate=220-age). All sessions will be monitored by a licensed physical therapist. Immediately after the warm-up, a standard flexibility routine will be performed to minimize the risk of injury. Then, the aerobic training protocol will be performed. The aerobic training program will follow the general guidelines established by the American College of Sports Medicine. Training will be performed using a standard stationary bicycle. Aerobic/endurance exercise will be performed with large muscle groups. Each subject will complete three supervised training sessions per week for 12 months. Strength training will be performed using Keiser equipment. Selected muscle groups will be trained alternating upper and lower exercises in the following order: 1) hip extension, 2) lateral pull down, 3) knee extension, 4) elbow flexion, 5) knee flexion, and 6) chest press. Each repetition will include concentric and eccentric phases. Each muscle group will be trained individually 3 times per week, on alternate days. The subjects will perform three sets of 10 repetitions each for every muscle group, resting 2-3 seconds between repetitions, 2 minutes between sets, and 4 minutes between muscle groups. The 1 repetition maximum will be measured every 3-4 weeks for the first 6 months and it will be repeated again at the 9 and 12 month visits. The relative intensity will increase from 60-80% of the 1 repetition maximum over 6 months. Subjects not randomized to training will have a determination of 1 repetition maximum made at baseline, 6 and 12 months.