1. EFFECT OF A MICRONUTRIENT ON A DIABETIC COMPLICATION: SYSTEMATIC REVIEW
Pinki Mishra, Rizwana Parveen, Reema Singh, Shiekh Raisuddin, Nidhi B. Agarwal
Centre for Translational and Clinical Research, Jamia Hamdard, New Delhi , INDIA
Introduction
Results
Vitamin D levels were assessed and compared among control groups and in patients with and without retinopathy in the studies included in this systematic review.
Serum vitamin D level was negatively associated with diabetic retinopathy.
Diabetes mellitus (DM) is a complex, chronic, progressive disease, of multiple aetiologies characterized by chronic hyperglycemia leads to a reduction in quality of life and life expectancy.1
Low vitamin D status has been associated with increased risk of non-musculoskeletal diseases such as cancer, diabetes and multiple sclerosis2 Albeit, the underlying biological mechanisms are poorly understood, the association of low levels of serum 25-hydroxyvitamin D3 [25(OH)D3] concentrations with DM2 may be mediated through effects on glucose homeostasis and direct effect of vitamin D on the β-cell function, and thus insulin secretion.
Low vitamin D status has also been suggested to contribute insulin resistance and is associated with markers of impaired glucose metabolism, such as glycosylated hemoglobin.3
Moreover, an increased incidence of diabetic complications have been observed in DM2 patients with hypovitaminosis D.
Figure:1 Vitamin D levels in controls and in patients with and without diabetic retinopathy
Figure 2: Vitamin D levels in controls, patients with proliferative diabetic retinopathy and without diabetic retinopathy
Methodology
This systematic review was conducted to assess the association of hypovitaminosis D and DM2 complications.
A literature search in PubMed and MEDLINE, was conducted for clinical trials assessing the levels of vitamin and correlating the levels with diabetes complications, by applying predetermined inclusion and exclusion criteria.
Inclusion criteria
Studies with Vitamin D
Studies with retinopathy
Studies with type-2 diabetes
Exclusion criteria (n=61)
-Studies on type 1 diabetes
-Studies not related to diabetes retinopathy
-Studies not assessing vitamin d levels
-Pediatrics
-Retrospective study
-Studies reporting combined result on both type-1 and type-2 diabetes
-Studies reporting combined data on complications of diabetes
-Mean values of vitamin D levels not provided
Figure 3: Prevalence of vitamin D deficiency among the controls and in n patients with and without diabetic retinopathy
Figure 4 : Vitamin D levels in patients without retinopathy and in different grades of retinopathy4
Conclusion
The findings from the systematic review indicate that low vitamin D level may be considered a predictor of diabetic retinopathy; however, data from longitudinal and large cohort studies are needed. It is suggested that the levels of vitamin should be periodically screened in diabetics.
References
American Diabetes Association. Standards of Medical Care in Diabetes. Diabetes Care. 2014;37(Suppl 1).
J van der Schaft, HL Koek, E Dijkstra, HJJ Verhaar, YT van der Schouw et al. The association between vitamin D and cognition: A systematic review. Ageing Research Reviews. 2013;12:1013– 1023.
Christine D, Maria SP, Pal W and Philippe G. vitamin D Status in Relation to Glucose Metabolism and Type 2 Diabetes in Septuagenarians Diabetes Care. 2011;34:1284–1288.
Vitamin D deficiency increases the risk of retinopathy in Chinese patients with type 2 diabetes.He R, Shen J, Liu F, Zeng H, Li L, Yu H, Lu H, Lu F, Wu Q, Jia W. Diabet Med Dec;31(12):