Halef Okan DOGAN, Dilek BERKER, Fatma Meriç YILMAZ, Yüksel KOCA, Canan TOPCUOĞLU

Investigation of the relationship between TSH and serum lipids in patints with subclinical hypothyroidism and euthroid subjects

Amaç: Bu çalışmada subklinik hipotiroidi hastalarında ve ötroid bireylerde tiroid stimulan horman (TSH) düzeyi ile serum lipid düzeyleri arasındaki ilişki araştırılmıştır. Ayrıca serum lipid düzeyleri kullanılarak optimal serum TSH düzeyi belirlenmeye çalışılmıştır. Yöntem: Çalışmaya 213 subklinik hipotiroidi hastası ve 178 ötroid birey çalışmaya dahil edildi. Çalışmaya dahil edilen bireylerin serum lipid (total kolesterol, LDL kolesterol, HDL kolesterol ve trigliserid), tirotropin (TSH), serbest tiroksin [s(T4)] ve serbest triyiodotironin [s(T4)] düzeyleri laboratuvar informasyon sistemindent aranarak kaydedildi. Bulgular: Hasta ve ötroid kontrol grubu arasında LDL-C, total kolesterol, nonHDL-C ve total kolesterol/HDL-C düzeyleri yönünden istatistiksel olarak anlamlı farklılık gözlendi. Hem kontrol hem de hasta grubundaTSH düzeyi ile LDL-C, total kolesterol, non-HDL-C ve total kolesterol/HDL-C düzeyi arasında pozitif korelasyon saptandı. Farklı LDL-C düzeyleri cutoff olarak alındığında TSH düzeyleri için farklı pozitif olasılık oranları ile karşılaşıldı. Sonuç: TSH düzeyindeki normal sınırlar içinde kalan artışlarda da bazı lipid düzeylerinde artış saptandı. Bu durumun özellikle koroner kalp hastalığı için risk faktörüne sahip bireylerde önemli olabileceği düşünülmektedir.

Subklinik hipotiroidi hastalarında ve ötroid bireylerde TSH düzeyi ile serum lipid düzeyleri arasındaki ilişkinin araştırılması

Objective: Although the diagnosis and treatment of subclinical hypothyroidism (SH) primarily depend on the upper normal TSH serum concentration, there are not any well standardized reference limits to be used in the diagnosis and treatment of subclinical hypothyroidism.The aim of the study was to obtain data using serum lipid profile in order to optimize the target TSH levels especially for patients who have a high risk factor for atherosclerosis. Method: A total of 213 patients with the diagnosis of SH and 178 euthyroid subjects were included in the study. Serum lipid parameters and the concentrations of thyrotropin (TSH), and free thyroxin f(T4) and free triiyodotironin f(T3) were recorded. Results: Statistically significant difference was observed between patients and controls in terms of low density lipoprotein cholesterol (LDL-C), total cholesterol (TC), non-HDL-C and the ratio of TC/HDL-C. TSH level correlated significantly with LDL-C, TC, non-HDL-C and the ratio of TC/HDL-C in control and patient groups. According to LDL-C concentrations, different increased risk rate were observed in the presence of different TSH values. Conclusions: We found positive correlation between TSH and atherogenic lipids as expected. Moreover, our findings showed that lower TSH concentrations which are still considered as normal, are also associated with increased lipid values. This might be important especially for patients who have a high risk for atherosclerosis and cardiovascular diseases. Thus, treatment of patients with above upper normal limit of TSH according to risk category might be helpful to reduce the atherogenic process.

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