Are hsCRP Levels and LDL/HDL Ratio Better and Early Markers to Unmask Onset of Dyslipidemia and Inflammation in Asymptomatic Subclinical Hypothyroidism?

Abstract

The implications of subclinical hypothyroidism (SCH) are many amongst which the most important is progression to overt hypothyroidism. Other debatable aspects are its association with cardiovascular risk, neuromuscular and psychiatric dysfunction, increased predisposition to developing metabolic syndrome and an underlying pro-inflammatory state. We aimed to study the lipid profile, lipoprotein(a) [Lp(a)] and hsCRP levels and insulin resistance in a group of patients with SCH in a referral hospital and see if any significant differences exist between them and euthyroids. This is a case-control study where the selection of controls and cases was based on the thyroid profile. Subjects were selected on their visit to clinical biochemistry lab for thyroid function tests. 33 euthyroids were taken as controls (Group I) and 38 patients comprising of subclinical hypothyroids were grouped as cases (Group II). Serum thyroid stimulating hormone (TSH) was in the range of 0.5-5.0 mIU/L for euthyroids and for subclinical hypothyroids the concentration of TSH was more than 5 mIU/L. The concentration of tri-iodothyronine (T 3 ) and thyroxine (T 4 ) were in normal reference range in both the groups. Individual lipid profile parameters failed to show a significant p value between cases and controls. The LDL/ HDL ratio was highly significant (p value \ 0.0001) and hsCRP was also statistically between the two groups (p value = 0.0054). Lp(a) and insulin resistance did not differ significantly. SCH is a common disorder that frequently progresses to overt hypothyroidism. This study underlines the importance of LDL/HDL ratio rather than measurement of individual lipid profile parameters in bringing to light the dyslipidemic state associated with SCH. Moreover the use of hsCRP to detect an underlying pro-inflammatory state in SCH can also be emphasized.

The Effect of Metformin Monotherapy on Biochemical Parameters Associated With Diabetes Mellitus, Kidney, Cardiac, Liver, Thyroid, and Reproductive Organ Functions in Pre- And Post-Menopause Women With Type 2 Diabetes Mellitus

“…However, previous studies have shown no changes in both FT3 and FT4 after 12 weeks of MMT, but our findings showed drop in values after 12 months. In our study too, we found out some decrease in FT3 after 6 months compared to diagnosis, but the decrease in values are not statistically significant [15,22]. FT4, one of the important thyroid hormones which are usually done along with TSH, all values were found to be perfectly normal, but at the lower MMT, but our study did not find such effects.…”

“…No significant was found between LP(a) and IR. Hence, LDL-c/HDL-c ratio may be useful in the diagnosis of SCH [15].…”

“…This study outcome is unable to explain this unusual findings but future studies are showing extended time after 12 months could possible establish the reasons and, may be the ratios will improve after 12 months of treatment. Previous studies have shown a correlation between LDL/HDL ratio to thyroid hormones, but we did not undertake this comparison [13][14][15].…”

Subclinical Hypothyroidism;

“…[26][27][28][29][30] Positive correlation of CRP with serum TSH (r= 0.626, P=0.0001) is a worth findings supported by previous studies. [29][30][31] Association of CRP with dyslipidemia has been reported previously [32][33][34] in SCH patients. A previous study 33 reported increased risk of atherosclerotic vascular disease in SCH patients as indicated by dyslipidemia and hsCRP.…”

Is Cardiovascular Risk Associated with Subclinical Hypothyroidism: Role of C Reactive Protein and Interleukin-6

“…Mahto M et al study stated that the elevated LDL-cholesterol/HDL-cholesterol ratio can highlight the cardiac risk and have the potential to become a part of the screening process of SCH patients along with CRP to detect the cardiovascular abnormality. 29 CHOD-POD method, GPO-PAP method and CHOD-POD/Phosphotungstate method respectively. Erba Chem, Germany kits were used for the estimation of lipid parameters.…”