Utility of Lipoprotein (a) as a Marker of Cardiovascular Disease Risk in Hypothyroid Patients

Aim: The aim of our study was to assess the utility of lipoprotein (a) as a reliable cardiovascular risk marker in hypothyroid patients. This involved estimation and comparison of lipoprotein (a) levels between hypothyroid patients and healthy adults. To correlate lipoprotein (a) [Lp(a)] with thyroid stimulating hormone was the other objective of this study.

Study Design: Case-control study.

Place and the Duration of the Study: Department of Biochemistry and Department of General Medicine, Rajarajeswari Medical College and Hospital, Bengaluru, between January 2014 and May 2014.

Methodology: Forty one individuals aged between 18 and 55 years, who were newly diagnosed with hypothyroidism were our cases. Twenty nine age and sex matched healthy volunteers constituted the controls. Serum Thyroid stimulating hormone (TSH), Free Thyroxine (FT4), Serum total cholesterol (TC), serum low density lipoprotein (LDL), serum high density lipoprotein (HDL), serum triglycerides (TGL) and serum Lipoprotein (a) were estimated by standard methods in cases and controls. The anthropometric data included measurement of weight and height of study subjects in order to calculate their body mass index (BMI).

Results: The mean ± SD of the lipid parameters (TC, LDL, VLDL, HDL and TGL) in both the groups were almost same and were at the upper limit of the reference range. The mean ± SD levels of Lp(a) in cases was 39.4±26.5 mg/dl and 18.1±7.4 mg/dl in controls. There was no correlation between lipoprotein (a) and thyroid stimulating hormone in both cases and controls.

Conclusion: Lipoprotein (a) levels are elevated in hypothyroidism and it can be considered as a reliable marker to detect cardiovascular disease risk in hypothyroid patients when estimated by a standard method.