Table ASummary of data on interventions and outcomes in patients with diabetes or impaired glucose tolerance

OutcomeBehavioral Changes (Data Almost Entirely From Systematic Reviews, RCTs)Intervention Medications (Data Almost Entirely From Systematic Reviews, RCTs)Bariatric Surgery (Data Primarily From Observational Studies)
Weight loss at 1 year2.8 kg for diet, exercise, behavioral vs. usual careWeight gain from 1 to 5 kg with some drugs. 2.8 kg weight loss with GLP-1R agonists; no weight change with metforminBMI loss of 5 to 7 kg/m2 (about 15 to 20 kg for someone 5 feet 6 inches tall)
Weight loss at 2 years2.7 kg for diet, exercise, behavioral vs. usual careData unavailableBMI loss of 4 to 8 kg/m2 (about 11 to 23 kg for someone 5 feet 6 inches tall)
Long-term weight loss (5 years and more)1.7 kg for diet, exercise, behavioral vs. usual care at 5 yearsFew data; the U.S. Diabetes Prevention Program Outcomes Study (DPPOS) found no significant change with metformin at 10 yearsBMI loss of 5.7 kg/m2 at 5 years, in one study of 29 LAGB patients
HbA1C, percentage of total hemoglobin, at 1 yearDecrease of 0.3 to 2.2 percentage pointsDecrease of 0.5 to 1.0 percentage pointsDecrease of 2.6 to 3.7 percentage points
HbA1C at 2 yearsNo significant changeData unavailableDecrease of 1.8 to 3.1 percentage points
HbA1C at 5 years and moreFew data; the U.S. Diabetes Prevention Program Outcomes Study (DPPOS) found HbA1C concentrations lower in behavioral group at 10 years (vs. placebo)Few data; the U.S. Diabetes Prevention Program Outcomes Study (DPPOS) found HbA1C concentrations lower in metformin group at 10 years (vs. placebo)Data unavailable
Other metabolic outcomes at 1 yearDiet improved fasting glucose (1.3%-36.6% reduction) and triglycerides (11.3%-58.9% reduction); the Spain PREDIMED study found Mediterranean diet reduced metabolic syndrome prevalence by 13.7% at 1 year; the Finnish Diabetes Prevention Study (DPS) found behavioral change reduced metabolic syndrome prevalence at 3.9 years (odds ratio: 0.62)Most medications had minimal effects on systolic & diastolic blood pressure (< 5 mmHg change); metformin and second-generation sulfonylureas generally decreased LDL cholesterol levelsMixed results, one RYGB and one BPD study reported slight increase in triglycerides at 1 year
Other metabolic outcomes at 5 years and moreData unavailableData unavailableOf 7 BPD patients followed, all had normal serum cholesterol and triglycerides
Microvascular outcomes (renal disease, neuropathy, retinopathy, etc.)Data unavailableU.K. Prospective Diabetes Study (UKPDS) found patients taking sulfonylurea, insulin, or metformin had 24% risk reduction for microvascular disease at 10 yearsData unavailable
Macrovascular outcomes (cardiovascular disease, stroke, heart attack)Few data; the China Da Qing Diabetes Prevention Study (CDQDPS) found no significant difference in first CVD event, CVD mortality and all-cause mortality between intervention and control groupMeta-analysis of 5 trials with 33,040 participants found that on an average A1C reduction of 0.9% there was a 19% reduction in non-fatal myocardial infarction and a 15% reduction on coronary heart disease, and no statistically significant effect on stroke or all-cause mortalityData unavailable
Prevention of diabetesHazard ratio 0.51 for behavioral interventions vs. standard advice at 1 to 5 years; the U.S. Diabetes Prevention Program (DPP) found diabetes incidence in 10 years reduced by 34% by behavioral change vs. placebo, and the China Da Qing Diabetes Prevention Study (CDQDPS) found it was 43% lower in behavioral group over 20 yearsHazard ratio 0.70 for oral medications vs. control at 1 to 5 years; the U.S. Diabetes Prevention Program (DPP) found diabetes incidence in 10 years reduced by 18% in the metformin group vs. placeboData unavailable

BMI = body mass index; BPD = biliopancreatic diversion with duodenal switch; CVD = cardiovascular disease; LAGB = laparoscopic adjustable gastric banding; LDL = low-density lipoproteins; RCT = randomized controlled trial; RYGB = Roux-en-Y gastric bypass

From: Executive Summary

Cover of Bariatric Surgery and Nonsurgical Therapy in Adults With Metabolic Conditions and a Body Mass Index of 30.0 to 34.9 kg/m2
Bariatric Surgery and Nonsurgical Therapy in Adults With Metabolic Conditions and a Body Mass Index of 30.0 to 34.9 kg/m2 [Internet].
Comparative Effectiveness Reviews, No. 82.
Maglione MA, Gibbons MM, Livhits M, et al.

PubMed Health. A service of the National Library of Medicine, National Institutes of Health.