Higher cholesterol levels linked to reduced fertility

A couple’s cholesterol levels may play a part in how long it takes them to conceive, according to a recent study.

The findings, independent of body mass index, "are the first to demonstrate that select serum lipids are associated with reduced couple fecundity as measured by a longer time to pregnancy," reported Enrique Schisterman, Ph.D., of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and his associates.

Between 2005 and 2009, the researchers tracked 501 couples who were attempting to conceive. They were followed for 12 months or until a pregnancy was detected with human chorionic gonadotropin (hCG). During follow-up, 69% of the couples became pregnant, 11% did not and 20% withdrew from the study.

All participants had a lipid analysis that included cholesterol, free cholesterol, phospholipids, triglycerides, and total lipids. For both men and women, age was significantly associated with free cholesterol levels, mean BMI increased as free cholesterol quartiles increased, and participants in lower quartiles for free cholesterol reported more vigorous exercise than did those in higher quartiles (J. Clin. Endocrinol. Metab. 2014 May 20 [doi:10.1210/jc.2013-3936]).

After adjustment for age, BMI, and race and education, free cholesterol (fecundity odds ratio 0.983) and total lipids (fecundity odds ratio .998) in women were significantly associated with time to pregnancy. No serum lipid components in men were significantly associated with time to pregnancy. With couples’ concentrations modeled together, free cholesterol was significantly associated with time to pregnancy (fecundity odds ratio 0.984), as was male free cholesterol (fecundity odds ratio 0.984).

"Of the five lipid components evaluated, free cholesterol was robustly associated with reduced fecundity when modeling female serum lipids individually or in a couple-based approach independent of BMI," the authors wrote. "Male free cholesterol concentrations were also an independent risk factor for reduced fecundability, irrespective of female lipid levels."

The study was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institutes of Health. The authors had no disclosures.

A couple’s cholesterol levels may play a part in how long it takes them to conceive, according to a recent study.

The findings, independent of body mass index, "are the first to demonstrate that select serum lipids are associated with reduced couple fecundity as measured by a longer time to pregnancy," reported Enrique Schisterman, Ph.D., of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and his associates.

Between 2005 and 2009, the researchers tracked 501 couples who were attempting to conceive. They were followed for 12 months or until a pregnancy was detected with human chorionic gonadotropin (hCG). During follow-up, 69% of the couples became pregnant, 11% did not and 20% withdrew from the study.

All participants had a lipid analysis that included cholesterol, free cholesterol, phospholipids, triglycerides, and total lipids. For both men and women, age was significantly associated with free cholesterol levels, mean BMI increased as free cholesterol quartiles increased, and participants in lower quartiles for free cholesterol reported more vigorous exercise than did those in higher quartiles (J. Clin. Endocrinol. Metab. 2014 May 20 [doi:10.1210/jc.2013-3936]).

After adjustment for age, BMI, and race and education, free cholesterol (fecundity odds ratio 0.983) and total lipids (fecundity odds ratio .998) in women were significantly associated with time to pregnancy. No serum lipid components in men were significantly associated with time to pregnancy. With couples’ concentrations modeled together, free cholesterol was significantly associated with time to pregnancy (fecundity odds ratio 0.984), as was male free cholesterol (fecundity odds ratio 0.984).

"Of the five lipid components evaluated, free cholesterol was robustly associated with reduced fecundity when modeling female serum lipids individually or in a couple-based approach independent of BMI," the authors wrote. "Male free cholesterol concentrations were also an independent risk factor for reduced fecundability, irrespective of female lipid levels."

The study was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institutes of Health. The authors had no disclosures.

A couple’s cholesterol levels may play a part in how long it takes them to conceive, according to a recent study.

The findings, independent of body mass index, "are the first to demonstrate that select serum lipids are associated with reduced couple fecundity as measured by a longer time to pregnancy," reported Enrique Schisterman, Ph.D., of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, and his associates.

Between 2005 and 2009, the researchers tracked 501 couples who were attempting to conceive. They were followed for 12 months or until a pregnancy was detected with human chorionic gonadotropin (hCG). During follow-up, 69% of the couples became pregnant, 11% did not and 20% withdrew from the study.

All participants had a lipid analysis that included cholesterol, free cholesterol, phospholipids, triglycerides, and total lipids. For both men and women, age was significantly associated with free cholesterol levels, mean BMI increased as free cholesterol quartiles increased, and participants in lower quartiles for free cholesterol reported more vigorous exercise than did those in higher quartiles (J. Clin. Endocrinol. Metab. 2014 May 20 [doi:10.1210/jc.2013-3936]).

After adjustment for age, BMI, and race and education, free cholesterol (fecundity odds ratio 0.983) and total lipids (fecundity odds ratio .998) in women were significantly associated with time to pregnancy. No serum lipid components in men were significantly associated with time to pregnancy. With couples’ concentrations modeled together, free cholesterol was significantly associated with time to pregnancy (fecundity odds ratio 0.984), as was male free cholesterol (fecundity odds ratio 0.984).

"Of the five lipid components evaluated, free cholesterol was robustly associated with reduced fecundity when modeling female serum lipids individually or in a couple-based approach independent of BMI," the authors wrote. "Male free cholesterol concentrations were also an independent risk factor for reduced fecundability, irrespective of female lipid levels."

The study was supported by the Eunice Kennedy Shriver National Institute of Child Health and Human Development and the National Institutes of Health. The authors had no disclosures.