Fig. 1

Summary of the prevailing opinions, potential mechanisms and clinical implications for the seasonal differences in blood lipids. 1) Prevailing opinions:.Most reports supports that the levels of LDL-C and cholesterol were elevated in winter and were decreased in summer [6, 7, 12,13,14,15,16,17]. For HDL-C and triglyceride, the existing results were contradictory [5, 9, 10, 13, 15, 16, 18, 20,21,22,23,24,25,26,27, 31, 32, 38].. 2) Potential mechanisms:.Accumulating evidence pointed towards an array of mechanisms for the seasonal variations of serum lipids, including air temperature, physical activity, diet, blood volume, liver production of cholesterol and activity of lipid receptors and lipases, as well as other life style-related factors [6, 11, 25, 33, 34].. 3) Clinical implications: The seasonal variations of serum lipids could lead to the diagnostic and treatment biases, which include the delayed diagnosis and treatment as well as the aggressive use of lipid-lowering therapy. Firstly, for the individuals whose lipid measures approach or reach the lower limit for therapy in the summer, another measurement is highly recommended in the winter. Otherwise, a fraction of this group might experience a missed diagnosis and delayed treatment. Secondly, for the subjects whose lipid levels just reach or are slightly above the lower limit for therapy in the winter, there might be a bias toward improperly classifying a portion of this group as hypercholesterolemic in the winter. Thirdly, a higher possibility of treatment failure is expected when patients initiate treatment for hypercholesterolemia during the summer and undergo follow-up during the winter [35,36,37].