Indan Journal of Medical Research Indan Journal of Medical Research Indan Journal of Medical Research Indan Journal of Medical Research
  Home About us Editorial board Search Ahead of print Current issue Archives Submit article Instructions Subscribe Contacts Login  
  Home Print this page Email this page Small font sizeDefault font sizeIncrease font size Users Online: 3834       

   Table of Contents      
COMMENTARY
Year : 2013  |  Volume : 138  |  Issue : 6  |  Page : 829-830

Vitamin-D & prediabetes: a promising ménage in the Indian Scenario


1 Department of Clinical & Surgical Medicine Unit of Endocrinology University Federico II of Naples, Italy
2 IRCCS SDN Foundation Naples, Italy

Date of Web Publication11-Feb-2014

Correspondence Address:
Silvia Savastano
Department of Clinical & Surgical Medicine Unit of Endocrinology University Federico II of Naples
Italy
Login to access the Email id

Source of Support: None, Conflict of Interest: None


PMID: 24521621

Rights and PermissionsRights and Permissions

How to cite this article:
Savastano S, Somma CD, Colao A. Vitamin-D & prediabetes: a promising ménage in the Indian Scenario. Indian J Med Res 2013;138:829-30

How to cite this URL:
Savastano S, Somma CD, Colao A. Vitamin-D & prediabetes: a promising ménage in the Indian Scenario. Indian J Med Res [serial online] 2013 [cited 2019 Nov 18];138:829-30. Available from: http://www.ijmr.org.in/text.asp?2013/138/6/829/126821

Vitamin-D deficiency represents a global health problem affecting individuals across all life stages [1] . Hypovitaminosis D is largely due to inadequate cutaneous production from 7-dehydrocholesterol and, to a lesser degree, from low dietary intake or impaired intestinal absorption of vitamin-D. The physiological production in the skin of this vitamin-hormone is affected by the exposure to sunlight which depends, in turn, on seasonal changes, latitude, clothing, skin pigmentation and use of sunscreens. However, many newly recognized interfering factors are gaining growing attention, such as obesity epidemic and high levels of environmental pollution. These new factors pave the way for the association of vitamin-D deficiency to the worldwide detrimental changes in lifestyle related to the effect of industrialization and migration to urban environment from rural settings. Thus, obesogenic environment and industrial pollution might exert an important role in promoting vitamin-D deficiency in countries with developing economy, like India, where industrialization and urbanization are growing at an exponential rate.

A remarkable similarity exists between a number of the risk factors for hypovitaminosis D and those for diabetes. Despite the lack of large well-planned national studies truly representative of India as a whole, the estimates of existing studies regarding the number of people with diabetes in India reported by Anjama et al[2] is 1.1-2.9 per cent, with a projection of around 51 million people with diabetes. In line with other developing countries, India is currently facing an epidemiologic transition of communicable vs non-communicable diseases [2] .

Vitamin-D has been primarily recognized for its role in calcium homeostasis and bone health since its identification in 1921 [3] . In recent years, along with the discovery of the growing number of extra-skeletal pleiotropic effects of this hormone, it has become increasingly evident that vitamin-D regulates the functions of over 200 genes. In particular, vitamin-D deficiency is associated with insulin resistance, diabetes mellitus and increased cardiovascular risk. The concurrent global epidemics of type 2 diabetes and vitamin-D deficiency raise the question whether the vitamin-D deficiency might be included among the risk factors for diabetes [4] . Indeed, robust epidemiological evidence demonstrates the association between circulating 25-hydroxyvitamin-D [25(OH)D] and risk of type 2 diabetes [5] . Recently, the European Prospective Investigation into Cancer (EPIC)-Norfolk study reported an inverse association between circulating 25(OH)D and incident type 2 diabetes [6] . However, data from this very comprehensive meta-analysis, that failed to demonstrate any evidence of causality between vitamin-D status and risk for type 2 diabetes, cannot be extrapolated fully to other ethnic groups.

Prediabetes indicates a category of individuals with impaired fasting glucose or impaired glucose tolerance (IGT), whose risk for the future development of diabetes is relatively high [7] . In that, it would be of strategic importance to unravel the state of vitamin-D deficiency among individuals with prediabetes. So far, differences among the cohort studies in race, body weight, glucose homeostasis, or exposure to sunlight might account for the substantial degree of controversy surrounding the prevalence of vitamin-D deficiency in patients at risk for diabetes, such as those having IGT or metabolic syndrome.

In the present issue, Dutta et al[8] have investigated the relationship between vitamin-D status and insulin resistance among adult individuals with prediabetes by evaluating the circulating levels of 25(OH)D, as the best indicator of vitamin D status [9] . In the study, the authors found that the occurrence of vitamin-D deficiency/insufficiency was 73.25, 66.6 and 78.57 per cent among individuals with prediabetes, diabetes and normal glucose tolerance, respectively, and that the prevalence of severe vitamin-D deficiency (<10 ng/ml) was about twice for individuals with prediabetes compared with both normal and diabetic groups. The prevalence of vitamin-D deficiency/insufficiency reported by Dutta et al[8] appeared in line with data obtained in India from various studies published earlier [10],[11] . Despite the adequate sunshine in India, there are many factors involved in the epidemic of hypovitaminosis D, and it has been well summarized elsewhere [12] . Using the classification proposed by Holick et al[13] , the authors evidenced that individuals with severe vitamin-D deficiency have the highest insulin resistance. Because of the limited sample size, the association between vitamin-D status and 1-hour post-load glucose ≥155 mg/dl, a parameter considered as a strong predictor for future risk of type 2 diabetes [14] , did not reach a statistical significance. Of interest, Dutta et al[8] also showed that the association between vitamin-D deficiency and measures of insulin resistance in their prediabetic individuals was independent of BMI and HbA1c. It is well-known that vitamin-D status is inversely related to body fat. Various factors, including the predominant storage of this fat soluble vitamin in the adipose tissue, have been proposed for this negative association. The independent association between vitamin-D deficiency and measures of insulin resistance could support the hypothesis that hypovitaminosis D might represent per se an adjunctive risk factor for the progression to overt diabetes and suggested that the determination of serum 25(OH)D could provide a practical complementary approach in the early diagnosis of type 2 diabetes.

Based on the data presented by Dutta et al[8] , it is tempting to speculate that worsened insulin resistance in prediabetes individuals with lower vitamin-D actually resulted in increased progression to diabetes. However, the cross-sectional design of the present study did not allow to unravel any causal association between insulin resistance and risk for progression to diabetes, being this report a pilot study to provide initial data on the relationship of insulin resistance with vitamin-D status primarily in individuals with prediabetes. Thus, the question about the putative inclusion of vitamin-D status as an independent risk for type 2 diabetes remains unsolved. Further studies, including a more careful evaluation of the "Calcium-vitamin D-parathyroid hormone" endocrine axis, are mandatory to pinpoint the real extent of the relationship between 25(OH)D and the risk for diabetes in the Indian scenario [12] and to clarify the possible preventive role of vitamin-D supplementations among prediabetes individuals.

 
   References Top

1.Holick MF, Chen TC. Vitamin-D deficiency a worldwide problem with health consequences. Am J Clin Nutr 2008; 87 : 1080S-6S.  Back to cited text no. 1
    
2.Anjana RM, Ali MK, Pradeepa R, Deepa M, Datta M, Unnikrishnan R, et al. The need for obtaining accurate nationwide estimates of diabetes prevalence in India - rationale for a national study on diabetes. Indian J Med Res 2011; 133 : 369-80.  Back to cited text no. 2
    
3.Hossein-Nezhad A, Holick MF. Vitamin-D for Health: A Global Perspective. Mayo Clin Proc 2013; 88 : 720-55.  Back to cited text no. 3
    
4.Mitri J, Muraru MD, Pittas AG. Vitamin D and type 2 diabetes: a systematic review. Eur J Clin Nutr 2011; 65 : 1005-15.   Back to cited text no. 4
    
5.Song Y, Wang L, Pittas AG, Del Gobbo LC, Zhang C, Manson JE, et al. Blood 25-hydroxy vitamin D levels and incident type 2 diabetes: a meta-analysis of prospective studies. Diabetes Care 2013; 36 : 1422-8.   Back to cited text no. 5
    
6.Forouhi NG, Ye Z, Rickard AP, Khaw KT, Luben R, Langenberg C, et al. Circulating 25-hydroxyvitamin-D concentration and the risk of type 2 diabetes: results from the European Prospective Investigation into Cancer (EPIC)-Norfolk cohort and updated meta-analysis of prospective studies. Diabetologia 2012; 55 : 2173-82.   Back to cited text no. 6
    
7.American Diabetes Association Diagnosis and classification of diabetes mellitus. Diabetes Care 2013; 36 (Suppl 1): S11-S66.  Back to cited text no. 7
    
8.Dutta D, Maisnam I, Shrivastava A, Sinha A, Ghosh S, Mukhopadhyay P, et al. Serum vitamin-D predicts insulin resistance in individuals with prediabetes. Indian J Med Res 2013; 138 : 853-60.  Back to cited text no. 8
    
9.Holick MF. Vitamin D deficiency. N Engl J Med 2007; 357 : 266-81.   Back to cited text no. 9
    
10.Goswami R, Mishra SK, Kochupillai N. Prevalence & potential significance of vitamin D deficiency in Asian Indians. Indian J Med Res 2008; 127 : 229-38.  Back to cited text no. 10
    
11.Harinarayan CV, Joshi SR. Vitamin D status in India - its implications and remedial measures. J Assoc Physicians India 2009; 57 : 40-8.   Back to cited text no. 11
    
12.Londhey V. Vitamin D deficiency: Indian Scenario. J Assoc Physicians India 2011; 59 : 695-6.  Back to cited text no. 12
    
13.Holick MF. Vitamin D: Importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis. Am J Clin Nutr 2004; 79 : 362-71.  Back to cited text no. 13
    
14.Manco M, Panunzi S, Macfarlane DP, Golay A, Melander O, Konrad T, et al. One-hour plasma glucose identifies insulin resistance and beta-cell dysfunction in individuals with normal glucose tolerance: cross-sectional data from the relationship between insulin sensitivity and cardiovascular risk (RISC) study. Diabetes Care 2010; 33 : 2090-7.  Back to cited text no. 14
    




 

Top
 
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
    References

 Article Access Statistics
    Viewed656    
    Printed11    
    Emailed0    
    PDF Downloaded318    
    Comments [Add]    

Recommend this journal