Prospective cohort study of the relationship of markers of insulin resistance and secretion with weight gain and changes in regional adiposity.
OBJECTIVE
To examine whether fasting insulin concentrations and markers of first-phase insulin secretion are associated with weight gain and changes in distribution of adiposity over 4.4y.


METHODS
Longitudinal prospective population-based cohort study of middle-aged Caucasians.


METHODS
767 subjects (40-65y at baseline) were followed up for a mean of 4.4y.


METHODS
75 g oral glucose tolerance test performed at baseline and follow-up. Insulin was measured at fasting, and 30 and 120 min post-glucose load using a highly specific assay.


RESULTS
Fasting insulin levels were correlated with baseline weight (r = 0.32, P<0.001), as was the 30 min insulin incremental response (r = 0.17, P<0.001). Mean weight gain over the 4.4y of follow-up was 2.17 kg (range: -6.17-10.5 kg) for men and 2.49 kg (range: -7.41-12.39 kg) for women. In women, the 30 min insulin incremental response was negatively associated with percentage weight gain (P<0.001), but there was no relationship between fasting insulin levels and weight gain. The baseline fasting insulin was positively correlated with percentage increase in waist- hip ratio (r = 0.12, P = 0.01). In stratified analysis, this relationship was confined to women over the age of 50 y. However, in men, none of these relationships were demonstrable.


CONCLUSIONS
In middle-aged women reduced first-phase insulin secretion was associated with an increased risk of future weight gain, whereas fasting hyperinsulinaemia was associated with an increase in waist-hip ratio over time.
Gould
A J
AJ
Department of Clinical Biochemistry, University of Cambridge, Addenbrookes Hospital, UK.
Williams
D E
DE
Byrne
C D
CD
Hales
C N
CN
Wareham
N J
NJ
D000328:Adult; D000368:Aged; D015415:Biomarkers; D001823:Body Composition; D001824:Body Constitution; D015331:Cohort Studies; D005260:Female; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D007333:Insulin Resistance; D000078790:Insulin Secretion; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism*; D011446:Prospective Studies; D012737:Sex Factors; D015430:Weight Gain
D015415:Biomarkers; D007328:Insulin