Higher serum 25(OH)D level is associated with decreased risk of impairment of glucose homeostasis: data from Southwest China

Abstract

BackgroundRecent epidemiological studies have suggested inverse associations between vitamin D status and metabolic diseases including type 2 diabetes (T2DM). The aim of this study was to examine whether a higher serum 25-hydroxyvitamin D (25(OH)D) was associated with a more favorable glucose homeostasis among adults without diabetes in Southwest China.MethodsSerum 25(OH)D concentration was measured in a cross-sectional sample of 1514 adults without diabetes aged 25–65 years recruited from Southwest China. Indices describing glucose homeostasis included fasting plasma glucose (FPG), fasting insulin, glycated hemoglobin (HbA1c), the homeostatic model assessment 2-insulin resistance (HOMA2-IR) and odds of pre-diabetes. Data were analyzed by multivariable-adjusted regression models.ResultsThe average serum 25(OH)D was 22.66 ng/ml, and percentages of vitamin D deficiency [25(OH)D < 20 ng/ml], insufficiency [20 ≤ 25(OH)D ≤ 30 ng/ml] were 47.6 and 32.2%, respectively. Serum 25(OH)D was inversely associated with fasting insulin (P = 0.0007), HbA1c (P = 0.0001) and HOMA2-IR (P = 0.0007), but not with FPG, after adjusting for age, gender, monthly personal income, smoking status, energy intake, moderate-to-vigorous physical activity (MVPA) and waist circumference (WC). Compared with the lowest 25(OH)D tertile, the odds ratio for pre-diabetes in the highest tertile was 0.68 (95%CI: 0.47-0.99) after adjustment for cofounders. In the following stratified analyses according to weight status, we only observed this inverse association between serum 25(OH)D and pre-diabetes in overweight or obese adults (n = 629, P = 0.047), but not in their counterparts with BMI < 24 kg/m2.ConclusionsOur results advocate that a higher serum 25(OH)D level is associated with decreased risk of impairment of glucose homeostasis among adults without diabetes in Southwest China. Further studies are warranted to determine the role of vitamin D in glucose homeostasis.Electronic supplementary materialThe online version of this article (10.1186/s12902-018-0252-4) contains supplementary material, which is available to authorized users.

Vitamin D levels, prediabetes risk and hemoglobin A1c levels in young non‐diabetic Saudi women

“…Some of the observational and interventional studies have reported an association between vitamin D levels and prediabetes in obese individuals. Li et al 15 in a study involving 1,514 Chinese adults without diabetes mellitus, of whom 65% had prediabetes, found that poor vitamin D status was significantly related to an increased risk of prediabetes in the overweight or obese individuals (P = 0.047), but not in those with a BMI <24 kg/m 2 . In a study involving obese Swedish adolescents, a significant interaction effect was found between low vitamin D levels and impaired fasting glycemia 48 .…”

“…Although the relationship between vitamin D and insulin resistance is, relatively, better investigated in patients with diabetes mellitus, data from individuals with prediabetes are limited 3,4,7,8 . Some observational data have suggested that vitamin D levels are negatively correlated with the risk of prediabetes, and with hemoglobin A1c (HbA1c) levels in individuals with prediabetes 3,4 , particularly in obese individuals 15 . These findings, however, have been inconsistent among different populations 7 and in an ethnic subgroup analysis of large national cohorts 4 .…”

The Nutrition and Health in Southwest China (NHSC) study: design, implementation, and major findings

“…Up to now, six articles reporting on the NHSC baseline data have been published [14][15][16][17][18][19]. Different exposures have been investigated, and body composition and glucose homeostasis have been examined; the key findings are summarized in Table 3.…”

“…Li et al [17] Serum 25(OH)D level and risk of impairment of glucose homeostasis A higher serum 25(OH)D level is associated with decreased risk of impairment of glucose homeostasis among adults without diabetes in Southwest China.…”

“…It has been suggested that unhealthy diet and lifestyle play a significant role in the development of NCDs [3]. Compared to western populations, Asians appear to have a greater genetic predisposition to T2DM [4,5]. These ethnic differences in the associations of risk factors with NCDs may result from differences in genetic susceptibility to NCDs or from interactions between diet, lifestyle, and genetic background.…”