Associations of 25-hydroxyvitamin D with fasting glucose, fasting insulin, dementia and depression in European elderly: the SENECA study.
OBJECTIVE
The classical consequence of vitamin D deficiency is osteomalacia, but recent insights into the function of vitamin D suggest that it may play a role in other body systems as well. The objective of this study was to examine the association between 25-hydroxyvitamin D (25(OH)D) and markers of glucose metabolism (n = 593), global cognitive functioning (n = 116) and depression (n = 118) in European elderly participating in the SENECA study. Moreover, we wanted to explore whether the observed associations of 25(OH)D with depression and global cognitive performance were mediated by fasting plasma glucose (FPG) levels.


METHODS
Cross-sectional associations between 25(OH)D and FPG, fasting plasma insulin (FPI) and homeostatic model assessment-insulin resistance (HOMA-IR), a marker of insulin resistance, were estimated from multiple regression analyses. Associations of 25(OH)D with global cognitive functioning (Mini Mental State Examination) and depression (Geriatric Depression Scale) were examined using Poisson regression.


RESULTS
An inverse association was observed between 25(OH)D and FPG (β-0.001), indicating a 1 % decrease in FPG per 10 nmol/L increase in 25(OH)D, but after full adjustment for demographic factors, lifestyle factors and calcium intake, this association was not statistically significant (P = 0.07). Although participants with intermediate and high serum 25(OH)D levels showed a tendency towards a lower depression score after adjustment for demographic and lifestyle factors, RR and 95 % CI: 0.73 (0.51-1.04) and 0.76 (0.52-1.11), respectively, these findings were not statistically significant.


CONCLUSIONS
An inverse association of 25(OH)D with depression and FPG was observed, but this association was not statistically significant. There was no association between 25(OH)D with FPI and HOMA-IR or with global cognitive functioning. More studies are needed to further explore the possible role of vitamin D in the various body systems.
Division of Human Nutrition, Wageningen University, PO Box 8129, 6700 EV, Wageningen, The Netherlands. Elske.Brouwer@wur.nl
Elske M
EM
Brouwer-Brolsma
Edith J M
EJ
Feskens
Wilma T
WT
Steegenga
Lisette C P G M
LC
de Groot
D015652:25-Hydroxyvitamin D 2 / Q000097:blood; D000368:Aged; D000375:Aging; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D002112:Calcifediol / Q000097:blood; D003072:Cognition Disorders / Q000209:etiology*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003704:Dementia / Q000209:etiology*; D003863:Depression / Q000209:etiology*; D005060:Europe; D005260:Female; D006306:Health Surveys; D006801:Humans; D006943:Hyperglycemia / Q000209:etiology*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D014808:Vitamin D Deficiency / Q000097:blood / Q000503:physiopathology* / Q000523:psychology
D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D015652:25-Hydroxyvitamin D 2; D002112:Calcifediol