[Correlation between thyroid hormones and renal function in severe pre-eclampsia patients with hypothyroidism]

Abstract

Objective: To study effects of different degree of hypothyroidism in severe pre-eclampsia (S-PE) pregnant women on renal function and the correlation between them.

Methods: 46 S-PE patients with subclinical hypothyroidism (SCH) registered for treatment in the Shengjing Hospital of China Medical University from May 2011 to March 2013 were selected into SCH group, and 23 S- PE with overt hypothyroidism (OH) were selected into OH group, and 109 S- PE with normal thyroid stimulating hormone (TSH) levels were selected into simple group. Thyroid hormone and kidney function tests were analyzed in pregnant women with S-PE. We made an analysis of the relative risk of the detection rate of abnormal renal function and also the relationship between the levels of thyroid hormone and serum uric acid, serum urea and creatinine in patients with S- PE.

Results: (1) In SCH group serum TSH was (6.1±3.2) mU/L, free triiodothyronine (FT3) was (4.0±0.6) pmol/L, free thyroxine(FT4)was (11.8±1.5) pmol/L; in OH group serum TSH was (5.2±1.3) mU/L, FT3 was (3.7±0.6) pmol/L, FT4 was (9.3±0.5) pmol/L; in simple S-PE group serum TSH was (1.9±0.8) mU/L, FT3 was (4.0±0.8) pmol/L and FT4 was (11.9±1.9) pmol/L. TSH in SCH group was significantly higher than that in simple S-PE group (P>0.01), the difference of in SCH and OH group were not statistically significant (P>0.05). The difference of FT3 in three groups were not statistically significant (P < 0.05); FT4 in OH group was significantly lower than thoes in SCH and simple groups (P < 0.05). (2) Serum uric acid, creatinine and urea levels in OH group was(436±114),(75±15)µmol/L and (6±3)mmol/L, in simple S-PE group they were(378±114), (65±22) µmol/L and (5±3)mmol/L. In comparison, the differences was statistically significant(P < 0.05). The differences were not statistically significant in SCH and OH groups (P > 0.05).(3)The abnormal detection rate of uric acid was significantly higher in SCH than that in OH group [46% (21/46) versus 22% (5/23), OR = 3.0, P < 0.05]. The comparison of remaining index has no statistical significance(P > 0.05).(4)In SCH group there was a significant inverse correlation of serum FT3 with serum urea levels, serum creatinine and serum uric acid (r = -0.32, -0.58, -0.35, P < 0.05). There was not a correlation of serum TSH, FT4 with indicators of renal function (P > 0.05). In OH group there was a negative correlation between FT3 and serum creatinine concentrations (r = -0.40, P < 0.05). In OH group there was not a correlation of FT3 with serum uric acid and urea(P > 0.05). There was a positive correlation between TSH and serum creatinine in simple S-PE group (r = 0.20, P = 0.04). There was not a correlation between TSH and serum urea(r = 0.04, P = 0.65), and serum uric acid (r = 0.12, P = 0.20).

Conclusions: There was effect of different hypothyrosis state in pre-eclampsia patients on renal function. Serum uric acid, urea and creatinine concentrations in S-PE pregnant women with OH were significantly higher than those in simple S-PE group with normal TSH. There was a negative correlation between FT3 and serum creatinine in S- PE. Hence the thyroid function should be regularly monitored in S- PE patients to find damage of renal function and management hypothyrosis.