Serum vitamin D concentration does not predict insulin action or secretion in European subjects with the metabolic syndrome.
OBJECTIVE
To investigate the relation between serum concentration of 25-hydroxyvitamin D [25(OH)D] and insulin action and secretion.


METHODS
In a cross-sectional study of 446 Pan-European subjects with the metabolic syndrome, insulin action and secretion were assessed by homeostasis model assessment (HOMA) indexes and intravenous glucose tolerance test to calculate acute insulin response, insulin sensitivity, and disposition index. Serum 25(OH)D was measured by high-performance liquid chromatography/mass spectrometry.


RESULTS
The 25(OH)D(3) concentration was 57.1 +/- 26.0 nmol/l (mean +/- SD), and only 20% of the subjects had 25(OH)D(3) levels > or =75 nmol/l. In multiple linear analyses, 25(OH)D(3) concentrations were not associated with parameters of insulin action or secretion after adjustment for BMI and other covariates.


CONCLUSIONS
In a large sample of subjects with the metabolic syndrome, serum concentrations of 25(OH)D(3) did not predict insulin action or secretion. Clear evidence that D vitamin status directly influences insulin secretion or action is still lacking.
Gulseth
Hanne L
HL
Department of Clinical Endocrinology, Oslo University Hospital Aker, University of Oslo, Oslo, Norway. h.l.gulseth@medisin.uio.no
Gjelstad
Ingrid M F
IM
Tierney
Audrey C
AC
Lovegrove
Julie A
JA
Defoort
Catherine
C
Blaak
Ellen E
EE
Lopez-Miranda
Jose
J
Kiec-Wilk
Beata
B
Risérus
Ulf
U
Ris
Ulférus
U
Roche
Helen M
HM
Drevon
Christian A
CA
Birkeland
Kåre I
KI
D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D024821:Metabolic Syndrome / Q000097:blood*; D008875:Middle Aged; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
D014807:Vitamin D; C104450:25-hydroxyvitamin D