Rajarajeswari Medical College and Hospital, Bangalore.
J Assoc Physicians India. 2022 Apr;70(4):11-12.
By definition, subclinical hypothyroidism refers to biochemical evidence of thyroid hormone deficiency in patients who have few or no apparent clinical features of hypothyroidism.The subclinical hypothyroidism is diagnosed mostly by biochemical tests, in which most of the patients have a serum TSH(5-10) levels elevated above the normal reference range but serum free T3 and free T4 are normal. In subclinical hypothyroidism, most of the patients have few or no signs of thyroid dysfunction. Hence, subclinical hypothyroidism is essentially a laboratory diagnosis.
The study was undertaken in Rajarajeswari medical college and hospital, Bangalore. It is a case-control study, comparing 50 SCH patients, selected based on the TSH values (5-10 µIU/ml) and 50 Euthyroid(EU) patients, matched for age and gender. Data was based on history, clinical examination, thyroid function, lipid profiles and Body mass index(BMI). Student's t, chi-square tests was used for computation of p values.
Dyslipidemia was significant in SCH patients compared to the control group. Further analysis of dyslipidemia showed that, total cholesterol, VLDL and LDL were all significantly elevated in cases as compared to controls with a statistical significance (p<0.001). Comparing the triglycerides, cases had higher values with statistical sig- nificance of (p=0.121). HDL was found to be reduced in cases with a statistical sig- nificance of (p=0.004). Even though 50% of cases had BMI >25 (kg/m2), it did not show any statistical significance when comparing with the TSH values. Similarly, though cases had an elevated TC,LDL,VLDL and reduced HDL, when correlating with the BMI, had no much statistical significance in both the cases and controls except for LDL which showed statistical significance of (p=0.044) in SCH cases. All the lipid variables were compared with TSH values, divided into two groups 5-8µIU/ ml and >8µIU/ml. Our study results have shown that the LDL hypercholesteremia (78.9%) was predominant followed by high Total cholesterol(42%) in SCH cases with TSH >8 (µIU/ml). Low HDL (<40 mg/dl) was seen in 57.9% of SCH cases with TSH >8(µIU/ml).
SCH is common in females, in the reproductive age group and elderly women.As SCH is asymptomatic, and more of a lab diagnosis, regular screening for thyroid dis- orders forms an important part of thyroid disease management. Dyslipidemia is common in SCH patients. Further, as the dyslipidemia is seen to increase with higher TSH values,SCH needs to be treated to prevent the complications of dyslipidemia. Is considered as atherogenic condition as it increases overall cardiovascular risk. It's important to assess lipid profile and CVS risk in these patients.
亚临床甲状腺功能减退症是指患者存在甲状腺激素缺乏的生化证据,但仅有少数或无明显的甲状腺功能减退症临床特征。亚临床甲状腺功能减退症主要通过生化检测来诊断,其中大多数患者的血清促甲状腺激素(TSH)(5-10)水平高于正常参考范围,但血清游离三碘甲状腺原氨酸(FT3)和游离甲状腺素(FT4)正常。在亚临床甲状腺功能减退症中,大多数患者仅有少数或无甲状腺功能减退的迹象。因此,亚临床甲状腺功能减退症本质上是一种实验室诊断。
该研究在班加罗尔的拉贾拉杰什瓦里医学院和医院进行,是一项病例对照研究,比较了 50 名亚临床甲状腺功能减退症(SCH)患者和 50 名甲状腺功能正常(EU)患者,这些患者的 TSH 值(5-10 µIU/ml)。这两组患者在年龄和性别上是匹配的。数据基于病史、临床检查、甲状腺功能、血脂谱和体重指数(BMI)。使用学生 t 检验和卡方检验来计算 p 值。
与对照组相比,SCH 患者的血脂异常更为显著。对血脂异常的进一步分析显示,与对照组相比,病例组的总胆固醇、极低密度脂蛋白(VLDL)和低密度脂蛋白(LDL)均显著升高,且具有统计学意义(p<0.001)。与对照组相比,病例组的甘油三酯水平也较高,且具有统计学意义(p=0.121)。病例组的高密度脂蛋白(HDL)水平降低,且具有统计学意义(p=0.004)。尽管 50%的病例组 BMI>25(kg/m2),但与 TSH 值相比,并无统计学意义。同样,尽管病例组的 TC、LDL、VLDL 升高,HDL 降低,但与 BMI 相关时,除 LDL 外,病例组和对照组均无明显统计学意义,LDL 具有统计学意义(p=0.044)。将所有血脂变量与 TSH 值进行比较,并将其分为两组,5-8µIU/ml 和>8µIU/ml。我们的研究结果表明,SCH 患者中以 LDL 高胆固醇血症(78.9%)为主,其次是总胆固醇升高(42%),TSH>8µIU/ml。TSH>8µIU/ml 的 SCH 患者中,57.9%的 HDL<40mg/dl。
SCH 在女性、生育年龄组和老年女性中较为常见。由于 SCH 无症状,更多的是实验室诊断,因此定期筛查甲状腺疾病是甲状腺疾病管理的重要组成部分。SCH 患者常伴有血脂异常。此外,随着 TSH 值的升高,血脂异常也会增加,因此需要治疗 SCH 以预防血脂异常的并发症。它被认为是一种动脉粥样硬化状态,因为它会增加整体心血管风险。评估这些患者的血脂谱和心血管风险非常重要。