Increased energy expenditure in poorly controlled Type 1 (insulin-dependent) diabetic patients.
Level 4 - case-series / case-control
Small pre-post interventional study without a concurrent randomized control group.
PubMed 6147290 · doi:10.1007/BF00253494
What was done
Basal energy expenditure was measured in 10 C-peptide-negative Type 1 diabetic patients during poor glycemic control and compared to predicted values based on age, sex, and body surface area. Measurements of energy expenditure, protein turnover, and hormone concentrations (glucagon, cortisol, growth hormone, triiodothyronine) were repeated following intravenous insulin treatment.
What was found
Basal energy expenditure in poorly controlled patients was 2042 +/- 62 kcal/24 h, significantly higher than the predicted 1774 +/- 52 kcal/24 h (p < 0.01). Intravenous insulin treatment significantly decreased energy expenditure to 1728 +/- 19 kcal/24 h (p < 0.01), matching predicted values. Uncontrolled diabetes was associated with increased protein turnover and increased plasma glucagon, with no significant increase in plasma cortisol, growth hormone, or triiodothyronine concentrations.
Why it matters
This study shows that poorly controlled Type 1 diabetes is a hypermetabolic state that can be rapidly normalized with insulin, providing a metabolic explanation for diabetes-related weight loss.
Limits
The sample size is very small (n = 10), and the study compared participants against predicted formulas rather than a concurrent matched control group. The exact mechanistic contributions (e.g., gluconeogenesis, sympathetic activity) were not definitively established in the abstract.
Cited by
- supports A study by Nair and colleagues demonstrated that insulin administration in type 1 diabetes begins to reduce the elevated metabolic rate within minutes.