title: Plasma HDL-cholesterol and triglycerides, but not LDL-cholesterol, are associated with insulin secretion in non-diabetic subjects.
abstract: OBJECTIVE
  Experimental data support the notion that lipoproteins might directly affect beta cell function, however clinical data are sparse and inconsistent. We aimed at verifying whether, independently of major confounders, serum lipids are associated with alterations in insulin secretion or clearance non-diabetic subjects.
  
  
  METHODS
  Cross sectional and observational prospective (3.5yrs), multicentre study in which 1016 non-diabetic volunteers aged 30-60yrs. and with a wide range of BMI (20.0-39.9kg/m2) were recruited in a setting of University hospital ambulatory care (RISC study).
  
  
  METHODS
  baseline fasting lipids, fasting and OGTT-induced insulin secretion and clearance (measured by glucose and C-peptide modeling), peripheral insulin sensitivity (by the euglycemic clamp). Lipids and OGTT were repeated in 980 subjects after 3.5years.
  
  
  RESULTS
  LDL-cholesterol did not show independent associations with fasting or stimulated insulin secretion or clearance. After accounting for potential confounders, HDL-cholesterol displayed negative and triglycerides positive independent associations with fasting and OGTT insulin secretion; neither with insulin clearance. Low HDL-cholesterol and high triglycerides were associated with an increase in glucose-dependent and a decrease in non-glucose-dependent insulin secretion. Over 3.5years both an HDL-cholesterol decline and a triglycerides rise were associated with an increase in fasting insulin secretion independent of changes in body weight or plasma glucose.
  
  
  CONCLUSIONS
  LDL-cholesterol does not seem to influence any major determinant of insulin bioavailability while low HDL-cholesterol and high triglycerides might contribute to sustain the abnormalities in insulin secretion that characterize the pre-diabetic state.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Italy. Electronic address: andrea.natali@med.unipi.it.
authors.forename: Andrea
authors.initials: A
authors.lastname: Natali
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Baldi
authors.affiliation: Service Endocrinologie-Diabétologie, Centre Hospitalo-Universitaire (CHU), University Rennes 1, Rennes, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Bonnet
authors.affiliation: Institute of Cardiovascular and Medical Sciences BHF Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK.
authors.forename: John
authors.initials: J
authors.lastname: Petrie
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Trifirò
authors.affiliation: Department of Clinical and Experimental Medicine, University of Pisa, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Tricò
authors.affiliation: CNR Institute of Neuroscience, Padova, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Mari
mesh_terms: D000328:Adult; D015992:Body Mass Index; D002096:C-Peptide / Q000378:metabolism; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood*; D003430:Cross-Sectional Studies; D005260:Female; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000378:metabolism*; D050417:Insulin-Secreting Cells / Q000378:metabolism; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014280:Triglycerides / Q000097:blood*
chemical_list: D002096:C-Peptide; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D007328:Insulin; D008055:Lipids; D014280:Triglycerides
keywords: HDL-cholesterol; Insulin secretion in vivo; Lipoproteins; Triglycerides; ß-cell function