Results of use of metformin and replacement of starch with saturated fat in diets of patients with type 2 diabetes.
OBJECTIVE
To improve glycemic control by substituting saturated fat for starch, to identify any adverse effect on lipids masked by the extensive use of metformin and lipid-lowering drugs, and to attempt to separate dietary effects from effects of multiple drugs.


METHODS
We undertook a retrospective review of medical records of patients who completed 1 year of follow-up after dietary prescription. The study subjects included 151 patients in the diet group (whose dietary instructions included high saturated fat but starch avoidance) and 132 historical control subjects (who were allowed unlimited monounsaturated fat but had restriction of starch in their diets).


RESULTS
Hemoglobin A1c (HbA1c) levels improved in both study groups (-1.4 +/- 0.2% [P<0.001]; 95% confidence interval [CI], -1.9 to -0.9). Use of metformin was associated with a decrease in HbA1c (-0.12 +/- 0.003%/mo [P<0.001]; 95% CI, -0.17 to -0.07). The diet group had an additional decrease of -0.7 +/- 0.2% (P<0.001; 95% CI, -1.1 to -0.3). Weight increase was associated with the use of insulin (+0.3 +/- 0.07 kg/mo [P<0.001]; 95% CI, 0.2 to 0.5), sulfonylurea (+0.18 +/- 0.06 kg/mo [P<0.01]; 95% CI, 0.05 to 0.30), and troglitazone (+0.7 +/- 0.2 kg/mo [P<0.005]; 95% CI, 0.3 to 1.2). Although not statistically significant, metformin therapy showed a trend for weight loss (-0.14 +/- 0.08 kg/mo; P = 0.07). An additional weight loss was noted in the diet group (-2.65 +/- 0.62 kg [P<0.001]; 95% CI, -3.87 to -1.44). Hydroxymethylglutaryl-coenzyme A reductase inhibitor use was associated with reduced total cholesterol level (-1.7 +/- 0.6 mg/dL per month [P<0.005]; 95% CI, -2.9 to -0.5). The diet group had an additional decrease of -13.0 +/- 4.5 mg/dL (P<0.001; 95% CI, -21.9 to -4.1). No significant effect of the diet on triglyceride, low-density lipoprotein, or high-density lipoprotein levels was detected.


CONCLUSIONS
Addition of saturated fat and removal of starch from a high-monounsaturated fat and starch-restricted diet improved glycemic control and were associated with weight loss without detectable adverse effects on serum lipids.
Hays
James H
JH
Christiana Care Health Services, Inc., Cardiology Research, Newark, Delaware 19718, USA.,
Gorman
Robert T
RT
Shakir
K M M
KM
D002784:Cholesterol / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D002839:Chromans / Q000627:therapeutic use; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000628:therapy*; D004041:Dietary Fats / Q000008:administration & dosage*; D005260:Female; D015248:Gemfibrozil / Q000627:therapeutic use; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D008055:Lipids / Q000097:blood; D008297:Male; D008687:Metformin / Q000627:therapeutic use*; D008875:Middle Aged; D012189:Retrospective Studies; D013213:Starch / Q000008:administration & dosage*; D013844:Thiazoles / Q000627:therapeutic use; D045162:Thiazolidinediones; D014280:Triglycerides / Q000097:blood; D000077288:Troglitazone; D015431:Weight Loss
D002784:Cholesterol; D008078:Cholesterol, LDL; D002839:Chromans; D004041:Dietary Fats; D015248:Gemfibrozil; D006442:Glycated Hemoglobin; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D007004:Hypoglycemic Agents; D008055:Lipids; D008687:Metformin; D013213:Starch; D013844:Thiazoles; D045162:Thiazolidinediones; D014280:Triglycerides; D000077288:Troglitazone