A Review of Synchronous Findings of Hypothyroidism and Cholelithiasis.

Cholelithiasis is considered to be the most common biliary pathology. They have been categorized into three types, which are pigment stones, cholesterol stones, and mixed types of stones with varying incidence. The condition may be asymptomatic for significantly long durations and in most cases, the presence of gall stones is an incidental finding. The patients may present with pain in the abdomen in stages of cholecystitis or advanced stages or cases of gall stones causing the obstruction. Gallbladder stones are formed through a very complex procedure with the contribution of numerous factors, where the main initiating step is supposed to be the development of a state wherein there is supersaturation of the bile, which in turn gives rise to accumulation and stasis of the bile and the development of gall stones. One of the factors is said to be the hypothyroid state. Hypothyroidism itself is a significantly common endocrine disorder that affects almost every nucleated cell in the body. There is decreased efficacy of the thyroid gland. The serum T3 and T4 levels might be found on the lower side whereas thyroid-stimulating hormone (TSH) values are found to be high. In some of the cases, though the T3 and T4 levels are maintained within the normal limits, the TSH shows raised values, which are labeled as subclinical hypothyroidism. The state of hypothyroidism may act upon the amount of bile secretion, the flow of bile into the intestines, cholesterol metabolism, and the action of the sphincter of Oddi. Studies have shown results pointing towards the correlation between these two factors. The basic mechanism behind the correlation between cholelithiasis and hypothyroidism is supposed to be due to the action of the hypothyroid state on the functioning of the sphincter of Oddi. The hypothyroid state is supposed to be decreasing the tendency of the sphincter of Oddi to relax, thus causing stasis of the bile, which over time leads to initiation of supersaturation of the bile and formation of gall stones. Both subclinical hypothyroidism and clinical hypothyroidism are found to be significantly common in patients having cholelithiasis. We, in this review article, have taken into consideration various studies which have been performed regarding this topic worldwide. The studies have been performed on individuals who are already diagnosed with either of these diseases and are then screened for the presence of the other disease included in this study. The degree of correlation varies according to the location of the stones and their sizes. Though various studies show varying results to some extent, overall almost all the studies show significant pieces of evidence of the correlation between cholelithiasis and hypothyroidism.