PREVALENCE OF VITAMIN D DEFICIENCY AMONG MENOPAUSAL WOMEN AND ITS CORRELATION WITH DIABETES: A CROSS SECTIONAL DATA

Aim and objective: To evaluate prevalence of Vitamin D deficiency and establish any correlation between diabetes and vitamin D deficiency among postmenopausal women. Materials and Methods: The 25 – hydroxy vitamin D [25 (OH)D] concentrations were measured by competitive invitro quantitative immunoassay. The subjects were classified as vitamin – Ddeficient, insufficient or sufficient on the bases of 25 (OH) D concentrations of <20ng /ml, 20-30ng /ml or > 30ng /ml respectively. The apparently normal postmenopausal women (PMW) were subjected to fasting between vitamin D deficiency and diabetes. Results: Vitamin D deficiency was observed in 53.35% of the population, 19.48% had insufficiency and 26.83% had adequate Vitamin D levels. In 12.14% of the study population, fasting blood sugar levels were between the normal range which is 70-110 mg/ dl. Correlation between raised blood sugar levels and Vitamin D deficiency among PMW was non-significant (P =0.324). Conclusion:High prevalence of Vitamin D deficiency exists among apparently healthy. Indian PMW. However the current study failed to show any statistical correlation between Vitamin D deficiency and existence of diabetes, which may be due to small sample size.


INTRODUCTION
Vitamin D deficiency is a worldwide health problem, with a range of prevalence of 70% -100% in the general population. 1 Among Indian population, a prevalence of 50-90% has been reported. 2 Most of the researchers have uniformly reported a high prevalence of vitamin D deficiency, in various groups of the population such as school children, adolescents and pregnant women. 3,4,5. There are studies which report high prevalence of Vitamin D deficiency among postmenopausal women (PMW) from western world and India but data still remain scanty 6,7,8,9,10. Secondly, Vitamin D deficiency and diabetes mellitus are widely prevalent diseases during menopause. Furthermore, few epidemiological studies have shown an association of vitamin D deficiency and increased risk of chronic diseases like cancer, cardiovascular disease, type 1 and 2 diabetes (T1D, T2D) suggesting that vitamin D deficiency not only affects musculoskeletal health but also affects a wide range of acute and chronic diseases 11 .

MATERIALS AND METHODS
This cross-sectional, one year analysis, from June 2015-June 2016 was carried out among apparently healthy postmenopusal subjects (with one year of menstruation cessation) without known history of diabetes, thyroid, renal or hepatic disease or malignancy. Patients with history of surgery, hospitalization, or major medical illness within the past 1 year were excluded from the study patients on hormone replacement therapy, glucocorticoids, bisphosphonates, terip aratide and other drugs affecting bone metabolism were excluded as well. Surgical and other iatrogenic causes of menopause were also excluded from the current study.
Intake of conventional calcium / vitamin D supplements was not considered an exclusion criterion. All subjects were enrolled after taking a written informed consent. The 25hydroxy vitamin D [25 (OH) D] concentrations were measured by competitive in-vitro quantitative immunoassay in human serum and Cob as e analyses (Roche) Kit. Inter -assay Coefficient of Variability (CV) was 9.9% and intra-assay CV was 5. 7% in the current analysis.
The minimal detectable limit of the 25 (OH) D assays was 1.5ng/ ml. The subjects were classified as vitamin D-deficient Available Online at http://www.recentscientific.com International Journal of Subjects were included in a cross -sectional manner from general population. The apparently normal PMW were subjected to fasting blood glucose level tests and vitamin D levels to analyse any correlation between the two states. After inclusion in the study they were called on next day for fasting blood samples. Blood glucose levels were estimated by glucose oxidize method and normal reference range was defined as 70 -110 mg/dl.
Fasting blood was collected and 2ml serum prepared and collected using standard sampling tubes containing separating gel before subjecting them for analysis for vitamin D levels. The data was analysed by one laboratory after standardization.

Statistical Analysis
The data was categorized as mean+SD and N (%) and correlation between vitamin D and diabetes was established by using Pearson coefficient correlation test. The P value < 0.05 was considered significant.  (Table 1) Out of the study population, 12.14% had fasting blood glucose > 110 mg/dl and rest of the population was between the normal range (70-110 mg/dl). The age wise distribution of the population and their vitamin D levels and fasting blood glucose levels are depicted in the correlation between raised blood glucose ( Table 2) levels and vitamin D deficiency among PMW was non-significant [(P = 0.324). Table 3].

DISCUSSION
Vitamin D deficiency is reported in epidemic proportion, with a prevalence of 70% -100% in the general population both in urban setting and across all socioeconomic strata. 1 Study similar to the current study carried in past have reported very high prevalence of vitamin D deficiency among PMW from western world and India. [6][7][8][9][10] In a study from Europe carried among women aged over 80 years the prevalence of 25 (OH) Inadequacy was 80.9% and 44.5% when considering cut-offs of 75 and 50 n mol/L, respectively. 6 Results similar to our study were reported among urban central south Chinese PMW indicating 72. 1% women to be vitamin D deficient [25 (OH) D < 50 n mol/L]. 14 Vitamin D deficiency was seen in 83.7% of the subjects (< 20ng/ml) at baseline among Indian PMW as reported by one of 82% recent Indian study. 15 Similarly about 82% of the study group had varying degrees of low 25 (OH) D levels among Indian PMW who were on insufficienct calcium and high in phytate diet. 7 While comparing women of reproductive age (WR) group with PMW both, WR and in PMW 25 (OH) D deficiency (< 20mg/ml), insufficiency (20-30mg/ml) and replete states (> 30 mg/ml) were seen in 76%, 16.5%, 7.5% vs. 70%, 23% and 7% respectively. 16 Unlike our study PMW with established osteoporoses recorded serum vitamin D to be deficient in two third of patients. (17) Thereby indicating that prevention and early detection of hypovitaminosis D is the key to reduce the incidence of osteoporosis among PMW.  International Journal of Recent Scientific Research Vol. 8, Issue, 3, pp. 15909-15912, March, 2017 15911 | P a g e In another study no evidence for a clinically important association between serum 25 (OH) D levels and menopauserelated symptoms in PMW was observed. The current aspect was beyond the preview of the current study hence not studied. 10 Interestingly results of current study pointed that commonest age affected with vitamin D deficiency is 50-60 years followed by 45 -50 and least affected with vitamin D deficiency was above 60 years.
The results are in accordance with the study of Asadi M et al (2013) 18 wherein they showed a statistically significant positive correlation between vitamin D concentration and age in late postmenopausal period. The possible reasons for this may be increasing medical attention in the form vitamin D prophylaxis along with calcium supplementation being received by advancing age people worldwide.
Currently study failed to establish any statistical correlation between vitamin D and diabetes unlike various previous studies. In women, diabetes risk significantly increases in the lowest 25 (OH) D quintile. In men, 25 (OH) D levels has not been shown associated with diabetes incidence. 19 High prevalence of vitamin D deficiency in patients with type 2 diabetes mellitus (T2DM) and particularly in patients with T2DM and CVD has been reported. 20 Healthy adults with higher serum 25 (OH) D levels had significantly lower 60 min, 90 min and 129 min postprandial glucose levels and significantly better insulin sensitivity than those who were vitamin D deficient. 21 The researchers have also reported that with metformin, which improves insulin sensitivity by 13%, higher vitamin D status correlated with a 60% improvement in insulin sensitivity. In a recent clinical trial in women with T2D, vitamin D supplementation was shown to improve insulin sensitivity by 21%. 22 Another study suggested that vitamin D deficiency is a potential risk factor for obesity and development of insulin resistance leading to T2D. 23 Most recently Hiran V et al. 24 , documented that low levels of 25 (OH)D and active 1, 25-Dihydroxyvitamin D is independently associated with T2DM in older Australian men. These variations might be due to the fact that the above mentioned studies were largely epidemiological in nature with different study design taking all men and women without definite age-group into account unlike our study being restricted to PMW.
However, in the study by Song BM et al. 25 , vitamin D has not been shown to be independently associated with insulin resistance in Korean men and women like our study.
Similarly in a recent meta-analysis of prospective cohort studies no association been between vitamin D intake and T2D has been established. 26 In another study no correlation was established between 25 (OH) D level with markers of insulin resistance (1R) in postmenopausal Indian women. 15 The insulin resistance of the obese subjects who were vitamin D deficient and insufficient did not statistically differ from those with vitamin D sufficiency in the study of Torun E et al. 27 Low 25 (OH) D levels were not related with higher insulin resistance in obese children and adolescents. In obese subjects, insulin resistance was affected more from BMI. Chacko SA et al. 28 documented that higher, serum 25 (OH) D concentrations may be inversely associated with adiposity, triglycerides, triglyceride:high density lipoproteins (HDL) cholesterol ratio, and metabolic syndrome but are not associated with low-density lipoproteins (LDL) and HDL cholesterol, insulin, glucose in PMW.
Dong JY et al. 29 reported that vitamin D intake during early life although may be associated with a reduced risk of T1D. However, there is not enough evidence for an association between maternal intake of vitamin D and risk of T1D in the off spring.
Sample size of the study group is very small to generalize results of this study group to Indian population. The study has not taken other variable and risk factor into consideration for finding any correlation. However, it addresses a major nutrition related health problem in Indian population, which needs attention.

CONCLUSION
High prevalence of vitamin D deficiency exists among PMW. However the current study failed to show any statistical correlation between vitamin D deficiency and existence of diabetes, which may be due to small sample size.