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Vitamin D insufficiency and cognitive impairment in Asians: a multi‐ethnic population‐based study and meta‐analysis
Author(s) -
Annweiler C.,
Milea D.,
Whitson H. E.,
Cheng C.Y.,
Wong T.Y.,
Ikram M. K.,
Lamoureux E. L.,
Sabanayagam C.
Publication year - 2016
Publication title -
journal of internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.625
H-Index - 160
eISSN - 1365-2796
pISSN - 0954-6820
DOI - 10.1111/joim.12491
Subject(s) - medicine , meta analysis , population , cognition , vitamin d and neurology , demography , ethnic group , cognitive impairment , epidemiology , gerontology , psychiatry , environmental health , sociology , anthropology
Background The relationship between vitamin D insufficiency and cognitive impairment remains equivocal in Asians. We examined the association between circulating 25‐hydroxyvitamin D (25 OHD ) concentration and cognitive performance in a large multi‐ethnic Singaporean population‐based study. We also conducted a meta‐analysis of 25 OHD concentrations amongst cognitively impaired older adults in Asia. Methods Our population‐based cross‐sectional study included 2273 persons ≥60 years of age from the Singapore Epidemiology of Eye Diseases ( SEED ) study (mean ± SD age 70.4 ± 6.2 years; 44.7% female), who were categorized according to 25 OHD concentration (i.e. ≤10, 10.1–20 and >20 ng mL −1 ). The 25 OHD concentration was measured and adjusted to reflect a deseasonalized value. Cognition was assessed using the total and domain scores of the Abbreviated Mental Test ( AMT ). Global cognitive impairment was defined as AMT score of ≤6 if 0–6 years of education and AMT score of ≤8 if >7 years of education. Fully adjusted multivariate models were used. We included seven studies in a meta‐analysis of 25 OHD and cognition in Asia (6068 participants; 1179 cognitively impaired cases). Results Participants with 25 OHD levels >20 ng mL −1 ( n = 1302) had higher AMT total scores (mean ± SD 8.5 ± 1.9) and were less likely to have cognitive impairment (14.1%) than participants with lower 25 OHD levels (overall P < 0.001, P ‐trend < 0.001). Deseasonalized 25 OHD concentration was associated with AMT score (β = 0.10 per 10 ng mL −1 , P = 0.035). Vitamin D insufficiency (25 OHD ≤20 ng mL −1 ) was associated with global cognitive impairment ( OR 1.56, P = 0.028). Specifically, 25 OHD concentration correlated with semantic memory ( r = 0.08, P = 0.009) and orientation in time ( r = 0.09, P = 0.003). In the meta‐analysis, the pooled mean 25 OHD difference was −6.83 ng mL −1 (95% confidence interval −11.36; −2.30), indicating lower 25 OHD concentrations amongst cognitively impaired compared to cognitively healthy participants in Asia. Conclusion Vitamin D insufficiency is associated with a greater likelihood of and more severe cognitive impairment in Asian populations.