Association between Serum Albumin and Hypothyroidism in Preeclampsia: A Case-control Study

Abstract

Introduction: Preeclampsia is a cause of high morbidity and mortality in pregnant women. Serum albumin is found to be low in preeclampsia. Few recent studies have shown a state of hypothyroidism in preeclampsia. Aim: To find the association between the serum albumin and thyroid hormone levels in preeclampsia and seek to find if hypoalbuminemia increases the risk of hypothyroidism. Materials and Methods: A case-control study was done at Department of Biochemistry and the Department of Obstetrics and Gynaecology of Government Medical College, Thiruvananthapuram, Kerala, with 40 preeclampsia cases and 40 normal pregnant controls, in 30-38 week gestation. Serum albumin and thyroid profile-Total T3, Total T4, Thyroid Stimulating Hormone (TSH), freeT3 (fT3), freeT4 (fT4) were tested. Statistical analysis was done with Student’s t-test, Chi-square, Fischer’s t-test and Pearson’s correlation coefficients. Results: The mean serum albumin was significantly lesser in preeclampsia (3.11±0.39) than in controls (3.7±0.14 g/dL). Thyroid hormones were significantly decreased in preeclampsia. TSH was significantly raised (3.76±1.55 mIU/L) in preeclampsia compared to normal pregnant ladies (2.3±0.94 mIU/L). In cases with hypoalbuminemia, risk for hypothyroidism was 2.85 times compared to those with normal albumin but was not statistically significant. In severe preeclampsia, there was a two times increased risk. There was a negative correlation of TSH and positive correlation for fT4 with serum albumin. However, this was statistically not significant. Conclusion: Hypothyroidism in preeclampsia was not significantly correlated with hypoalbuminemia in this study. Thus hypoalbuminemia did not significantly increase the risk for hypothyroidism in our study. Further studies are needed to determine the risk factors affecting thyroid function in preeclampsia.

Association of thyroid function test abnormalities with preeclampsia: a systematic review and meta-analysis

“…The results of this study showed that the higher TSH mean level in preeclamptic patients, which is consistent with other studies [ 35 , 64 , 82 ]. Even though placental function abnormalities can interfere with estrogen production, leading to decrease of TBG levels and it can be a reason for elevated TSH secretion by anterior pituitary [ 59 , 61 ] but in the some studies, TSH level in preeclamptic women was not higher than normal pregnant women [ 3 , 41 ].…”

“…The hypothesis appropriate to these conditions is that the conversion of T4 to T3 is impaired in the liver, which could be the reason for the low level of FT3 in women with preeclampsia [ 30 ]. No difference in FT3 between the two groups was observed in other studies [ 30 , 64 , 82 ]. The findings of present study showed lower mean FT4 level in preeclamptic patients is similar to the results of other studies [ 30 , 38 , 41 ] while finding of some investigations showed a higher mean FT4 level in preeclampsia [ 14 , 23 ].…”

“…According to other studies, women with preeclampsia have increased antiangiogenic factors, which in turn reduce nitric oxide production. This in turn reduces thyroid capillary flow, which can lead to hypothyroidism [ 82 ]. In a normal pregnancy, estrogen increases serum TBG, but in preeclampsia, lack of estrogen production leads to a decrease in TBG.…”

Prevalence of Hypothyroidism in Patients With Hyponatremia

“…According to a study, elders and females are more affected by hypothyroidism, and its prevalence is higher in subjects with chronic kidney disease (Singh et al, 2021). Moreover, TSH level is also significantly related to levels of serum albumin (Ahmad et al, 2019;Fukata et al, 2022;MuraleedharaN and BeeguM, 2021). After modifying these factors, the relationship between hypothyroidism and hyponatremia was significant.…”