Prospective 10-year evaluation of hypobetalipoproteinemia in a cohort of 772 firefighters and cross-sectional evaluation of hypocholesterolemia in 1,479 men in the National Health and Nutrition Examination Survey I

TLDR: Hypocholesterolemia in white and black men in NHANES I could not be attributed to hypocaloric intake or to protein, fat, or carbohydrate undernutrition, and may be associated with a reduced likelihood of coronary heart disease and with increased longevity.

Abstract: Our specific aim in a 10-year prospective study of 772 Cincinnati firemen (predominantly aged 26 to 46 years) was to determine the prevalence, attributes, and etiology of persistent hypobetalipoproteinemia, defined by entry low-density lipoprotein cholesterol (LDLC) less than 75 mg/dL A second specific aim was to cross-sectionally assess hypocholesterolemia (defined by total serum cholesterol [TC] 1, 130 v 133 mg/dL and 58 v 63 mg/dL) Compared with 32 men with entry LDLC less than 75 mg/dL but with less than 87% of follow-up LDLC less than 75 mg/dL, the 12 men with persistently low LDLC had lower mean Quetelet indices and diastolic blood pressure at entry (236 v 258, P = 056; 73 v 80 mm Hg, P = 03) and on follow-up study (245 v 269, P = 04; 72 v 79 mm Hg, P = 05) Of 12 men with persistently low LDLC, two had truncated apolipoprotein (apo) B (familial hypobetalipoproteinemia, two had the apo E genotype 2/3, and two had acquired hypobetalipoproteinemia that antedated mortality from melanoma by 9 years and from alcoholism by 2 years Comparable to white and black firemen aged 26 to 46 years, 29% and 36% of whom had entry serum TC less than 130 mg/dL, of 1,314 white and 165 black men in the NHANES I study (aged 26 to 46), 18% and 36% had hypocholesterolemia (entry TC 05) in men with entry TC less than 130 mg/dL compared with those with TC 130 to 230 or greater than 230 mg/dL Hypocholesterolemia in white and black men in NHANES I could not be attributed to hypocaloric intake or to protein, fat, or carbohydrate undernutrition There appear to be racial differences in the prevalence of hypocholesterolemia Blacks comprised 18% of the firemen's cohort but 42% of those with persistent hypobetalipoproteinemia; among NHANES I subjects, 36% of blacks were hypocholesterolemic versus 18% of whites Unless persistent hypobetalipoproteinemia reflects an underlying disease, alcoholism, etc, it is often heritable, and may be associated with a reduced likelihood of coronary heart disease (CHD) and with increased longevity