To investigate the relationship between 25-hydroxyvitamin D and metabolic syndrome (MS) in patients aged over 65 years.

A total of 164 patients aged over 65 years from June 2016 to June 2017 were divided into the MS group (64 cases) and non-MS group (100 cases) according to the diagnostic criteria of MS. The bone biochemical markers in the two groups were detected and compared. Meanwhile, all patients were divided into the deficiency group (148 cases) and non deficiency group (16 cases) according to 25- hydroxyvitamin D levels (<51 nmol/ L). The duration of diabetes, hypertension and hyperlipidemia, and the levels of fasting blood glucose, systolic blood pressure, diastolic blood pressure, body mass index (BMI), triglyceride, total cholesterol, low density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were detected. The relationship between 25-hydroxyvitamin D levels and above indexes were analyzed by Pearson correlation analysis.

The level of 25-hydroxyvitamin D was much lower in the MS group than in the non-MS group [(31 ± 7) mmol/L vs. (35 ± 9) mmol/L, t= 2.741, P= 0.007]. The levels of bone alkaline phosphates, serum calcium and serum phosphate showed no significant differences between the two groups (all P>0.05). Compared to the non deficiency group, the duration of hypertension was longer [(13.0 ± 3.7) years vs. (8.5 ± 2.2) years, t= 8.654, P<0.001], the levels of fasting blood glucose [(5.7 ± 0.8) mmol/L vs. (5.2 ± 0.6) mmol/L, t= 6.764, P= 0.011] and triglyceride [(1.6 ± 0.6) mmol/L vs. (1.0 ± 0.4) mmol/L, t= 1.608, P<0.001] were much higher, and the duration of hyperlipidemia was shorter [(1.58 ± 0.24) years vs. (1.97 ± 0.37) years, t= 2.452, P<0.001] in the deficiency group. However, the duration of diabetes, systolic blood pressure, diastolic blood pressure, BMI, total cholesterol, LDL-C and HDL-C all showed no significant differences between two groups (all P>0.05). Pearson correlation analysis showed that 25-hydroxyvitamin D levels were negatively correlated with the duration of hypertension (r=-0.102, P= 0.031), fasting blood glucose (r=-0.125, P= 0.028) and triglyceride (r=-0.139, P= 0.038), and positively correlated with HDL-C (r= 0.175, P= 0.024).

The levels of serum 25-hydroxyvitamin D is independent of BMI, and related to glucose metabolism and triglyceride metabolism in patients aged over 65 years. Supplementation of exogenous vitamin D may improve glucose and triglyceride metabolism in MS patients..