Rapid Decrease in HDL-C in the Puberty Period of Boys Associated with an Elevation of Blood Pressure and Dyslipidemia in Korean Teenagers: An Explanation of Why and When Men Have Lower HDL-C Levels Than Women.

Low serum high-density lipoproteins-cholesterol (HDL-C) levels and high blood pressure are linked to each other and are recognized as independent risk factors of cardiovascular disease and dementia. HDL can cross the blood-brain barrier to remove amyloid plaque and the blood-testis barrier to supply cholesterol for spermatogenesis, but LDL cannot. During the teenage period, between 10 and 19 years of age, the systolic blood pressure (BP) increased gradually to 7.9% in boys ( < 0.001), but not in girls ( = 0.141). The boys' group showed a remarkable decrease in the total cholesterol (TC) and HDL-C from 10 to 15 years of age ( < 0.001). After then, the TC level increased again at 19 years of age to the previous level ( < 0.001). On the other hand, the HDL-C level at 19 years of age in the boys' group was not restored to the previous level at 10 years of age. The girls' group maintained similar TC ( < 0.001) and HDL-C ( < 0.001) levels from 10 to 19 years of age. These results suggest there was a remarkable difference in cholesterol consumption, particularly in the HDL-C level between boys and girls during the pubertal period. Correlation analysis showed an inverse association between the HDL-C level and SBP in boys (r -0.133, < 0.001) and girls (r -0.065, = 0.009) from 10 to 19 years of age. Interestingly, only the boys' group showed an inverse association with the diastolic BP (r -0.122, < 0.001); the girls' group did not have such an association (r -0.016, = 0.516). In conclusion, the boys' group showed a sharp decrease in the HDL-C level from 10 to 15 years of age, whereas the girls' group showed an increase in the HDL-C level during the same period. These results explain why men have a lower serum HDL-C level than women in adulthood.