BACKGROUND:The national prevalence of goiters in the Philippines was 3.7% in 1987 and 6.7% in 1993. Since then, there has been no follow-up survey on goiter prevalence, nor has there been any national survey on the prevalence of abnormal thyroid dysfunction. The PhilTiDeS is a survey on the prevalence of both goiters and thyroid disorders in the Philippines.
OBJECTIVES:To determine the prevalence of various categories of abnormal thyroid dysfunction among the Filipino non-pregnant adult population and to describe the prevalence of thyroid enlargement in the Philippines in relation to thyroid dysfunction status.
MATERIALS AND METHODS:The PhilTiDes was a substudy of the 2008 National Nutrition and Health Survey (NNHeS), which covered all 17 regions and 80 provinces of the Philippines. It included all Filipino adults 20 years and older, who are non-pregnant and non-lactating. A standard questionnaire was used to collect data on previous diagnosis and current treatment for thyroid disorders, and neck examination by trained field personnel was done to assess the presence of goiter. Blood was extracted, processed and sent to an accredited laboratory for free T4 and TSH testing using micro-particle enzyme immunoassay.
RESULTS: A total of 4897 persons had thyroid function tests. Of these, 417 (8.53%) had thyroid function abnormalities with the most common abnormality being subclinical hyperthyroidism occurring in 5.33%. The other categories had the following prevalence: true hyperthyroidism 0.61% ; true hypothyroidism 0.41%; and subclinical hypothyroidism 2.18%. Majority of the population 4480 (91.47%) had normal thyroid function tests. Of those with subclinical hyperthyroidism, 55% are females with mean age of 48 years (95% CI 45.9-50.1 years) compared with the volunteers with normal thyroid function who were younger (mean age of 43.1, 95% CI 42.5-43.6 years). Out of the 7,227 volunteers who responded to the survey and clinical examination, a total of 674 (8.9%) had goiters. Out of the 674 subjects with goiters, 379 had diffuse enlargement (56%) while the rest had nodular goiter (44%). Among the sub-population (n= 4897) who underwent thyroid function testing, 9% of those with normal thyroid function tests have goiters.
CONCLUSION: The prevalence of thyroid function abnormalities in the Philippines is 8.53% with the greatest proportion of volunteers having subclinical thyroid disease. There is a low prevalence of both true or overt hyperthyroidism and hypothyroidism. In the larger survey, it was found that 8.9% of volunteers who were examined had goiters. The etiology of these goiters will need to be ascertained in future studies.