Abstract
To further explore the role of the β-cell as a pathogenic factor behind non-insulin-dependent diabetes mellitus (NIDDM), insulin secretion at modest hyperglycemia was examined in 15 healthy first-degree relatives of NIDDM patients and 13 anthropometrically and age-matched controls. The oral glucose tolerance test was normal in all, but the relatives had impaired insulin- stimulated glucose uptake (P < 0.05). During a constant intravenous glucose infusion we performed a time-series analysis of serum insulin in samples obtained at 1-min intervals for 75 min (60-135 min). The recently introduced scale- and model-independent statistic approximate entropy (ApEn) and the coefficient of variation for a 6- (9 and 15) point moving average (MA) were applied to test regularity and stationarity, respectively, of insulin secretion. Both ApEn and 6-point MA were able to significantly discern the insulin time series of the two groups (P < 0.05), demonstrating a higher degree of irregularity and nonstationarity among the offspring. Moreover, when the two complementary sets of statistics were combined into a single 'index of nonpulsatility,' an even more notable distinction was available (P < 0.01). No relationship was found between altered insulin secretion and insulin resistance. In conclusion, this experimental and statistical model demonstrates that the stimulated insulin secretion of glucose-tolerant relatives of NIDDM patients is characterized by disorderliness. Whether the model can predict the risk for developing a clinically important β-cell dysfunction remains to be clarified.
Original language | English (US) |
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Pages (from-to) | E218-E226 |
Journal | American Journal of Physiology - Endocrinology and Metabolism |
Volume | 272 |
Issue number | 2 35-2 |
DOIs | |
State | Published - Feb 1997 |
Keywords
- approximate entropy
- insulin pulsatility
- non-insulin-dependent diabetes mellitus
- prediabetic state
ASJC Scopus subject areas
- Endocrinology, Diabetes and Metabolism
- Physiology
- Physiology (medical)