Weight Loss Associated with Greater Reductions in Plasma Glucose Values with Impaired Fasting Glucose than with Normoglycemic for Obese Individuals.

Objective:  The prevalence of diabetes is increasing worldwide at an alarming rate. Impaired fasting glucose (IFG, fasting values 100-125 mg/dl) as well as high normal fasting plasma glucose (HNG, fasting values 91-99 mg/dl) are associated with higher risks for developing diabetes than normal glucose (NG, <91 mg/dl).

Method:  We assessed changes in plasma glucose value for two groups of patients treated in our intensive behavioral program (HMR^® Program for Weight Management^TM) using meal replacement shakes and entrees. First, 119 consecutive obese (OB, BMI>30 kg/m²) patients who completed 12 weeks of core classes and, second, 118 severely obese (SO, BMI>40 kg/m²) individuals who lost >100 pounds were evaluated.

Results:  The OB group included 23 diabetic, 21 IFG, 28 HNG, and 47 NG patients; these individuals lost, on average, 41 pounds in 18 weeks. The SO group included 24 diabetic, 34 IFG, 30 HNG, and 30 NG patients; these individuals lost, on average, 134 pounds in 43 weeks. Laboratory measurements were made biweekly or monthly. Diabetic patients were not analyzed because most were on medication at baseline and medicine was reduced in all and discontinued in half. Reductions in glucose values were significantly greater (P<0.001) for patients with IFG than NG for OB and SO; reductions in HNG were significantly greater than for NG with SO. For patients with IFG, glucose values decreased 21.9% + 3.5% (SE) for OB and 18.5 + 3.7% for SO. For patients with HNG values decreased 4.2 + 2.5% for OB and 12.9 + 1.8% for SO. For patients with NG values decreased 0.6 + 6.8% for OB and 0.6 + 2.3% for SO. Fasting serum triglyceride (FTG) values followed the same pattern but differences were not significant. SO persons with IFG has the highest FTG values (186 + 19 mg/dl) followed by HNG (161 + 13 mg/dl) compared to NG (137 + 11 mg/dl). Reductions in FTG were also greater in SO persons with IFG (-38 + 4%) than HNG (-33 + 5%) or NG (-32 + 6%). FTG in OB patients followed a similar pattern. Baseline systolic blood pressure and reductions followed a similar pattern in SO patients.

Conclusion:  These observations in OB and SO indicate that weight loss is accompanied by substantially larger improvements in cardiovascular risk factors in patients with IFG or HNG than with normoglycemia.