OBJECTIVE: To assess insulin secretion in normal glucose-tolerant Caucasian first-degree relatives of type 2 diabetes subjects and in matched normal glucose-tolerant control subjects and to compare insulin secretion as assessed using a hyperglycemic glucose clamp with insulin secretion as assessed using an oral glucose tolerance test (OGTT). RESEARCH DESIGN AND METHODS: Twenty-one first-degree relatives of type 2 diabetic subjects and 21 control subjects without a family history of type 2 diabetes, who were matched for sex, age, BMI, waist-to-hip ratio, and aerobic capacity, underwent a hyperglycemic glucose clamp (10 mmol/l, 180 min). An OGTT (75 g glucose in 300 ml water) was also performed. RESULTS: First-phase insulin release (plasma insulin, 0-10 min) was not different (multiple analysis of variance [MANOVA]: F = 2.63, P = 0.11). Second-phase insulin release was lower (MANOVA: F = 4.18, P = 0.047). Separate analyses of variance showed decreased plasma insulin levels from 120 min onward (all P < 0.05), decreasing to geometric mean (95% CI) levels of 330 (270-402) and 462 (366-582) pmol/l at 180 min in relatives and control subjects, respectively. The insulin sensitivity index (ISI) as assessed using a hyperglycemic clamp was not different between the two groups. Mean +/- SE ISI during the 3rd hour was 27.5 +/- 2.2 and 30.5 +/- 3.0 micrograms.kg-1.min-1.pmol-1.l-1 in relatives and control subjects, respectively (P > 0.20). At 90 min after the OGTT, log plasma insulin levels correlated significantly with second-phase insulin release as assessed using the hyperglycemic glucose clamp. CONCLUSIONS: Normal glucose-tolerant first-degree relatives of type 2 diabetic subjects have a decreased second-phase insulin release, compared with matched control subjects. After an OGTT, 90-min values of log plasma insulin and 90-min values of the ratio of log plasma insulin to blood glucose may be good indicators of insulin secretory properties in normal glucose-tolerant family members of type 2 diabetic subjects.
OBJECTIVE: To assess insulin secretion in normal glucose-tolerant Caucasian first-degree relatives of type 2 diabetes subjects and in matched normal glucose-tolerant control subjects and to compare insulin secretion as assessed using a hyperglycemic glucose clamp with insulin secretion as assessed using an oral glucose tolerance test (OGTT). RESEARCH DESIGN AND METHODS: Twenty-one first-degree relatives of type 2 diabetic subjects and 21 control subjects without a family history of type 2 diabetes, who were matched for sex, age, BMI, waist-to-hip ratio, and aerobic capacity, underwent a hyperglycemic glucose clamp (10 mmol/l, 180 min). An OGTT (75 g glucose in 300 ml water) was also performed. RESULTS: First-phase insulin release (plasma insulin, 0-10 min) was not different (multiple analysis of variance [MANOVA]: F = 2.63, P = 0.11). Second-phase insulin release was lower (MANOVA: F = 4.18, P = 0.047). Separate analyses of variance showed decreased plasma insulin levels from 120 min onward (all P < 0.05), decreasing to geometric mean (95% CI) levels of 330 (270-402) and 462 (366-582) pmol/l at 180 min in relatives and control subjects, respectively. The insulin sensitivity index (ISI) as assessed using a hyperglycemic clamp was not different between the two groups. Mean +/- SE ISI during the 3rd hour was 27.5 +/- 2.2 and 30.5 +/- 3.0 micrograms.kg-1.min-1.pmol-1.l-1 in relatives and control subjects, respectively (P > 0.20). At 90 min after the OGTT, log plasma insulin levels correlated significantly with second-phase insulin release as assessed using the hyperglycemic glucose clamp. CONCLUSIONS: Normal glucose-tolerant first-degree relatives of type 2 diabetic subjects have a decreased second-phase insulin release, compared with matched control subjects. After an OGTT, 90-min values of log plasma insulin and 90-min values of the ratio of log plasma insulin to blood glucose may be good indicators of insulin secretory properties in normal glucose-tolerant family members of type 2 diabetic subjects.
Authors: Deborah A Elder; Patricia M Herbers; Tammy Weis; Debra Standiford; Jessica G Woo; David A D'Alessio Journal: J Pediatr Date: 2012-01-10 Impact factor: 4.406
Authors: Leen M 't Hart; Annemarie M Simonis-Bik; Giel Nijpels; Timon W van Haeften; Silke A Schäfer; Jeanine J Houwing-Duistermaat; Dorret I Boomsma; Marlous J Groenewoud; Erwin Reiling; Els C van Hove; Michaela Diamant; Mark H H Kramer; Robert J Heine; J Antonie Maassen; Kerstin Kirchhoff; Fausto Machicao; Hans-Ulrich Häring; P Eline Slagboom; Gonneke Willemsen; Elisabeth M Eekhoff; Eco J de Geus; Jacqueline M Dekker; Andreas Fritsche Journal: Diabetes Date: 2009-10-06 Impact factor: 9.461
Authors: S A Schäfer; O Tschritter; F Machicao; C Thamer; N Stefan; B Gallwitz; J J Holst; J M Dekker; L M 't Hart; L M t'Hart; G Nijpels; T W van Haeften; H U Häring; A Fritsche Journal: Diabetologia Date: 2007-07-28 Impact factor: 10.122