Relationships between insulin metabolism, serum lipid profile, body fat distribution and blood pressure in healthy men.
Insulin resistance and hyperinsulinaemia may be important in a cluster of coronary heart disease-related metabolic disturbances known as the insulin resistance syndrome. Whether the relationships between insulin and other features of the syndrome are independent of the amount and distribution of body fat is uncertain. We have investigated these relationships in 103 healthy males, using dual-energy X-ray absorptiometry to measure body fat directly. Volunteers underwent an intravenous glucose tolerance test (IVGTT), from which insulin sensitivity, secretion and elimination were determined by mathematical modelling analysis. Independently of adiposity and body fat distribution, serum triglyceride concentration was correlated with fasting C-peptide concentration and second-phase intravenous glucose tolerance test insulin concentration (r = 0.42, P < 0.001; r = 0.28, P < 0.05). High density lipoprotein subfraction 2 (HDL2) cholesterol was correlated with fasting C-peptide, first-phase IVGTT insulin concentration, and the hepatic insulin throughout index (r = -0.15 -0.20, -0. 20 respectively, all P < 0.05). The association of HDL2 cholesterol with the hepatic throughput index was additionally independent of serum triglyceride concentration (r = -0.18, P < 0.05). Our results suggest that relative hyperinsulinaemia leads to elevated triglyceride concentration, independently of body fat mass and distribution. Furthermore, the independent association of HDL2 cholesterol with hepatic insulin throughput confirms that hepatic insulin processing may may directly influence lipoprotein metabolism.
Walton
C
C
Wynn Institute for Metabolic Research, London, UK.
Lees
B
B
Crook
D
D
Godsland
I F
IF
Stevenson
J C
JC
D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000033:anatomy & histology*; D000328:Adult; D000368:Aged; D001794:Blood Pressure; D001823:Body Composition; D002096:C-Peptide / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D008055:Lipids / Q000097:blood*; D008099:Liver / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D014280:Triglycerides / Q000097:blood
D002096:C-Peptide; D008076:Cholesterol, HDL; D007328:Insulin; D008055:Lipids; D014280:Triglycerides