Modest lifestyle intervention and glucose tolerance in obese African Americans.
OBJECTIVE
Previous studies have demonstrated the benefit of short-term diets on glucose tolerance in obese individuals. The purpose of this study was to evaluate the effectiveness of modest lifestyle changes in maintaining improvements in glucose tolerance induced by short-term energy restriction in obese African Americans with impaired glucose tolerance or type 2 diabetes mellitus.


METHODS
An intervention group (n = 45; 47 +/- 1 year [mean +/- SE]), 105 +/- 4 kg; body mass index: 39 +/- 1 kg/m(2)) received an energy-restricted diet (943 +/- 26 kcal/d) for 1 week, followed by a lifestyle program of reduced dietary fat (-125 kcal/d) and increased physical activity (+125 kcal/d) for 1 year. Body weight and plasma concentrations of glucose, insulin, and C-peptide during an oral glucose tolerance test were measured at baseline, 1-week, and 4-month intervals. A control group (n = 24; 48 +/- 1 year; 110 +/- 5 kg; body mass index: 41 +/- 2 kg/m(2)) underwent these measurements at 4-month intervals.


RESULTS
No changes in weight or glucose tolerance were observed in the control group. The intervention group had significant (p < 0.05) improvements in body weight and glucose tolerance in response to the 1-week diet, which persisted for 4 months (p < 0.001 vs. control for change in weight). A total of 19 subjects (42%) continued the intervention program for 1 year, with sustained improvements (weight: -4.6 +/- 1.0 kg; p < 0.001 vs. control; oral glucose tolerance test glucose area: -103 +/- 44 mM. min; p < 0.05 vs. control).


CONCLUSIONS
A modest lifestyle program facilitates weight loss and enables improvements in glucose tolerance to be maintained in obese individuals with abnormal glucose tolerance. However, attrition was high, despite the mild nature of the program.
Racette
S B
SB
Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110, USA. racettes@medicine.wustl.edu
Weiss
E P
EP
Obert
K A
KA
Kohrt
W M
WM
Holloszy
J O
JO
D000328:Adult; D001741:Black or African American; D000368:Aged; D019540:Area Under Curve; D001786:Blood Glucose / Q000032:analysis; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000178:diet therapy* / Q000208:ethnology; D004038:Diet, Reducing; D004041:Dietary Fats / Q000008:administration & dosage; D015444:Exercise; D005260:Female; D018149:Glucose Intolerance / Q000178:diet therapy* / Q000208:ethnology; D005951:Glucose Tolerance Test; D006801:Humans; D008019:Life Style; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000178:diet therapy / Q000208:ethnology; D015431:Weight Loss
D001786:Blood Glucose; D004041:Dietary Fats; D008055:Lipids