Prevalence of thyroid dysfunction in community of Duwakot, Bhaktapur

Background: Thyroid dysfunction is one of the major public health problems in the Nepalese community and of the common endocrine disorders diagnosed in community primary health care centres.  The aim of this study is to analyze the prevalence of Thyroid dysfunction in Duwakot, Nepal Materials and Methods: All the patients from Duwakot community who presented with the history of weight gain with tiredness and weight loss with palpitation were subjected to thyroid function test free triiodothyronine, free thyroxine and thyroid stimulating hormone. Results: Thyroid dysfunction was  found in 26% with M:F ratio of 1:5.  Subclinical hypothyroidism 62 (11.44%) was the most prevalent one followed by Primary hypothyroidism  48 (8.85%), primary hyperthyroidism 16 (2.95%) and subclinical hyperthyroidism 15 (2.76%). Conclusion: Thyroid dysfuntion has been observed despite of nationwide program regarding supplementation of micronutrient iodised salt. Key words: Euthyroid, Hyperthroidism, Hypothyroidism, Iodine, Prevalence, Thyroid dysfunction


INTRODUCTION
Thyroid dysfunction is one of the most common disorders, which is diagnosed among the patient seeking medical service in primary health care centers.Altered level of serum thyroid stimulating hormone (TSH) with normal or altered level of thyroid hormones which include free triiodothyronine (fT3) and free thyroxine (fT4) is defined as thyroid dysfunction. 1   Patients with thyroid dysfunction present with various non-specific symptoms and signs.Most common feature of hypothyroidism is tiredness and weight gain whereas features of hyperthyroidism are palpitation and weight loss. 2  Thyroid dysfunction increases the risk of osteoporosis, hyperlipidemia, hypercholesterolemia as well as cardiovascular and neuropsychiatric disorders. 3e micronutrient Iodine deficiency has been found to be the most common cause of thyroid disorders worldwide. 4heir manifestations vary considerably from area to area and are determined principally by the availability of iodine in the diet. 5most one-third of the world's population lives in areas of iodine deficiency.The WHO estimates that two billion people, including 285 million school-age children still have iodine deficiency. 5e Nepal Iodine Deficiency Disorders Status Survey (2005) monitoring the effectiveness of iodination program, indicated iodine status sufficiency overall and among rural children, and excess iodine intake among urban children. 6e 2016 Nepal Demographic and Health Survey (2016 NDHS) estimated that the vast majority of Nepalese households consume salt with iodine; 95% of children live in households that consume iodized salt.The percentage of children living in households that use iodized salt is lowest in State 6 (82%), in the Mid-Western region, and in the lowest wealth quintile. 7rious studies of thyroid dysfunction epidemiology have been done around the world which shows different results depending on different community including different ethnic group and influence of iodine intake.Studies of prevalence of thyroid dysfunction in Nepal have been done in only some part of the country.It has been found to be one of the major public health problems in the Nepalese community.
][10][11][12] In this post-iodinization era, the evaluation of thyroid dysfunction prevalence frequency needs to be studied as there are various evolving risk factors.Regular screening program has to be carried out for early recognition and proper management of thyroid dysfunction.Thyroid dysfunction can be identified with the thyroid function test and can be planned for the proper management.It helps timely treatment of the disorder and in prevention of consequences of thyroid dysfunction.This study was carried out to find out the prevalence of thyroid dysfunction among the patients from Duwakot community attending Kathmandu Medical College Teaching Hospital, Duwakot, Nepal.

MATERIALS AND METHODS
This is a hospital based cross-sectional observational study carried out in Duwakot, Nepal, for a period of 1 year from January 2016 to January 2017.All the patients from Duwakot community who presented with the history of weight gain with tiredness and weight loss with palpitation were subjected to thyroid function test which include free triiodothyronine (fT3), free thyroxine (fT4) and thyroid stimulating hormone (TSH).Permission was obtained from the Institutional review committee for the data collection and publication of the study.
Among the patients with primary hyperthyroidism male were 4 (25%) and female were 12 (75%).Subclinical hyperthyroidism was observed in 2 (13%) male and 13 (87%) female.Hypothyroidism was found more commonly among the age group of 45-54 years, subclinical hypothyroidism During our study period the total numbers of community people attending KMC Community Hospital were 31,381.Among those community patients who presented with the signs and symptoms suggestive of thyroid dysfunction screened which comprises 542 cases.
Out of 542 screened patients, 141 (26%) patients were found to have altered thyroid hormone level.This prevalence pattern is similar to the study done by Aryal M et al 1 and Regmi A et al 11 which shows 25% and 25.7 % respectively in the population of central Nepal.Various studies done in different geographical area with different ethnic community in south western, eastern and central region of Nepal have reported high prevalence of thyroid dysfunction.In south western Nepal, prevalence of thyroid dysfunction was 40.37% 8 in eastern Nepal 30.87% 10 and in central Nepal 29%. 12 Prevalence of thyroid dysfunction varies depending on different communities.Studies done in different part of the world shows different prevalence of thyroid function.A study done in India by Madhuvan HS et al 7 and Begum F 13 respectively revealed the prevalence of 25% and 21% whereas study done in Philippines by Carlos-Raboca J et al 19 shows prevalence of 8.53 percent.
In our study, among the screened patients, male patients comprise 16% and female patients comprise 84%.The ratio of male to female was M: F=1:5.Among patients of thyroid dysfunction, again male patients comprises 16% and female patients comprises 84% with the ratio of male female was M:F= 1:5.The prevalence of thyroid dysfunction was found to be higher in female population.In the studies done in various parts of Nepal by Aryal M et al 1 , Rohil V et al 9 and Jayan A et al 8 showed the percentage of thyroid dysfunction was higher in female.Similarly study done in other Asian countries like Pakistan by Khan A et al 14 and study done in India by Madhuvan HS et al 15 also concluded with the higher prevalence of female diagnosed with thyroid dysfunction.Even in the study done in US population by Hollowell JG et al 3 reported of female predominance with thyroid disorder.The ratio of prevalence of thyroid function has been seen higher in female in all the different national and international community.

CONCLUSION
Despite of nationwide programs regarding supplementation of micronutrient iodised salt, the prevalence of thyroid dysfunction has been observed higher in different communities of Nepal.The evaluation of thyroid dysfunction in larger population needs to be planned for future research.Proper implementation of screening program could reduce the economic and psychological burden to the individuals caused by the morbidity of thyroid dysfunction.
(TSH >) among 25-34 years, hyperthyroidism among 35-44 years & subclinical hyperthyroidism (TSH<) among the age group of 25-44 years.(fig.1)DISCUSSION Thyroid dysfunction is one of the most common endocrine disorders diagnosed in community primary health care centres in Nepal.It has been major public health problem in the Nepalese community.It is associated with significant Prevalence of Thyroid Dysfunction DOI : 10.3126/jpn.v7i2.18024consequences and usually has non-specific clinical presentation.Thyroid function test has been proven to be highly sensitive and specific in diagnosing thyroid dysfunction.

Figure 1 :
Figure 1: Distribution of thyroid dysfunction according to age.