This association can be hypothesized by Persian traditional medicine aspects of view on these diseases which both can be due to cold and wet temperament change.
However new evidences support this hypothesis as below:
O'BRIEN, T. I. M. O. T. H. Y., et al. "Hyperlipidemia in patients with primary and secondary hypothyroidism." Mayo Clinic Proceedings. Vol. 68. No. 9. Elsevier, 1993.
Mishkel, Maurice A., and Sandra M. Crowther. "Hypothyroidism, an important cause of reversible hyperlipidemia." Clinica Chimica Acta 74.2 (1977): 139-151.