Emerging evidence from in vivo and in vitro studies have shown that vitamin D may play an important role in the development of diabetic retinopathy (DR), but individually published studies showed inconclusive results. The aim of this study was to quantitatively summarize the association between vitamin D and the risk of diabetic retinopathy. We conducted a systematic literature search of Pubmed, Medline, and EMBASE updated in September 2016 with the following keywords: “vitamin D” or “cholecalciferol” or “25-hydroxyvitamin D” or “25(OH)D” in combination with “diabetic retinopathy” or “DR”. Fifteen observational studies involving 17,664 subjects were included. In this meta-analysis, type 2 diabetes patients with vitamin D deficiency (serum 25(OH)D levels <20 ng/mL) experienced a significantly increased risk of DR (odds ratio (OR) = 2.03, 95% confidence intervals (CI): 1.07, 3.86), and an obvious decrease of 1.7 ng/mL (95% CI: −2.72, −0.66) in serum vitamin D was demonstrated in the patients with diabetic retinopathy. Sensitivity analysis showed that exclusion of any single study did not materially alter the overall combined effect. In conclusion, the evidence from this meta-analysis indicates an association between vitamin D deficiency and an increased risk of diabetic retinopathy in type 2 diabetes patients.

ObjectivesThere are few data on the relationship between health-related quality of life (HRQoL) and physical activity among elderly individuals with pre-diabetes. This study aimed to determine if differences existed in HRQoL between individuals with pre-diabetes who were physically active compared with those who were physically inactive in rural China.Design, setting and participantsA cross-sectional survey was conducted among the elderly (≧60 years) in rural communities in Yiyang City of China. Multistage cluster random sampling was carried out to select 42 areas, and interviews were conducted among 434 elderly individuals with pre-diabetes. Pre-diabetes was screened using an oral glucose tolerance test.Main outcome measuresThe Medical Outcomes Study 36-Item Short Form Health Survey questionnaire was used to measure HRQoL. Physical activity was assessed using the International Physical Activity Questionnaire. Multivariate analysis of covariance (MANCOVA) was used to test for differences in HRQoL between the physically active group and the inactive group.ResultsA total of 434 individuals with pre-diabetes were included in this study. The physical component summary (PCS) score of HRQoL was 42.1±10.2 and the mental component summary score was 46.4±8.9. A median total physical activity of 524 metabolic equivalent-min/week was reported. A significant MANCOVA model (Wilks’ λ=0.962, F(2,423)=8.44, P<0.001) indicated that elderly individuals with pre-diabetes who were physically active reported higher PCS scores (Mdiff=5.2, P<0.001, effective size=0.47) compared with those physically inactive after adjusting for the following covariates: age, gender, marital status, education, smoking, chronic disease, body mass index and waist:hip ratio.ConclusionsThe HRQoL of elderly individuals with pre-diabetes is poor in rural China. These findings demonstrated that elderly individuals with pre-diabetes who were physically active had higher PCS scores than those who were physically inactive. Furthermore, these results support the rationale for developing a physical activity intervention for HRQoL of individuals with pre-diabetes.Trial registration numberChiCTR-IOR-15007033; Results.

No abstract

No abstract

Background. The prevalence of prediabetes has been increasing significantly in recent years. Individuals with prediabetes have an increased risk of developing diabetes and cardiovascular diseases. The objectives of this study were to identify risk factors for prediabetes and their interactions among the elderly in rural communities of Hunan Province and to provide a scientific basis for prediabetes prevention. Methods. A case-control study was conducted to explore risk factors for prediabetes among the elderly in rural areas. The general sociodemographic information, lifestyle behaviours, and physiological results of elderly individuals with prediabetes and controls were collected by a questionnaire and laboratory testing. Conditional logistic regression was performed to identify the risk factors for prediabetes among the elderly, and additive interactions were used to analyse the interactions between risk factors. Results. A total of 425 elderly subjects with prediabetes were included in the case group, and 425 elderly subjects with normal plasma glucose levels were included in the control group. The main risk factors for prediabetes among the elderly in rural communities of Hunan Province were a family history of diabetes (OR=2.48; 95% CI: 1.13, 5.46), physical inactivity (OR=3.27; 95% CI: 1.95, 5.49), a lack of health literacy on diabetes prevention and control (OR=3.26; 95% CI: 1.62, 6.55), hypertension (OR=2.01; 95% CI: 1.38, 2.93), overweight (OR=2.53; 95% CI: 1.67, 3.81), obesity (OR=3.08; 95% CI: 1.48, 6.40), and a high waist-to-hip ratio (WHR) (OR=2.26; 95% CI: 1.45, 3.51). Additive interactions for prediabetes were detected between a high WHR and physical inactivity, with a relative excess risk due to interaction (RERI) of 6.30 (95% CI: 0.42, 12.18), and between a high WHR and overweight or obesity, with an RERI of 2.92 (95% CI: 0.56, 5.29). Conclusion. The independent risk factors for prediabetes are a family history of diabetes, physical inactivity, a lack of health literacy on diabetes prevention and control, hypertension, overweight or obesity, and a high WHR. A high WHR has additive interactions with physical inactivity and overweight or obesity for the risk of prediabetes. These findings have significant implications for prediabetes prevention among the elderly in rural areas.