Study of biochemical prevalence indicators for the assessment of iodine deficiency disorders in adults at field conditions in Gujarat (India)

Abstract

The main objective of this study was to assess the severity of iodine deficiency disorders (IDD) in the adult populations of the Baroda and Dang districts from Gujarat, western India using biochemical prevalence indicators of IDD. The other aim of this study was to establish a biochemical baseline for adequate iodine intake as a result of program evolution in the face of multiple confounding factors, like malnutrition and goitrogens responsible for goiter. A total of 959 adults (16-85 years) were studied from two districts (Baroda and Dang) and data was collected on dietary habits, anthropometric and biochemical parameters such as height, weight, urinary iodine (UI) and blood thyroid stimulating hormone (TSH). Drinking water and cooking salt were analyzed for iodine content. All subjects, irrespective of sex and district, showed median UI = 73 microg/L and mean blood TSH +/- SD = 1.59+/-2.4 mU/L. Seven per cent of the studied population had blood TSH values > 5 mU/L. Females in Baroda and males from Dang district were more affected by iodine deficiency as shown by a lower median UI. Mean TSH was significantly higher in women from both districts as compared to men (P = 0.001). The blood spots TSH values > 5 mU/L were seen in 20% of women from Dang. The normative accepted WHO values for UI and TSH for the severity of IDD as a significant health problem are not available for target population of adults. Urinary iodine normative limits and cut-offs are established for school-aged children. Blood spot TSH upper limit and cut-off values are available for neonate populations. The IDD has not been eliminated so far, as more than 20% of both male and female subjects had UI < 50 microg/L. Males were more malnourished than females in both districts (P < 0.05). Pearl millet from Baroda contained flavonoids like apigenin, vitexin and glycosyl-vitexin. Dang district water lacked in iodine content. Iodine deficiency disorder is a public health problem in Gujarat, with the Baroda district a new pocket of IDD. High amounts of dietary flavonoids in Baroda and Dang, malnutrition and an additional lack of iodine in Dang water account for IDD.