Kathe A. Kelly

Lipids, Lipoproteins, and Sexual Maturation During Adolescence: The Princeton Maturation Study

Abstract This study encompassed a cross-sectional and longitudinal examination of schoolchildren as they entered into and passed through puberty, examining interrelationships between lipids, lipoproteins, and sexual maturation. In the first year of the study (1976), 529 schoolchildren in grades 5–12 participated; 203 were restudied in 1977, and 141 in 1978. At each yearly visit, the childrens stage of sexual maturation was assessed using the Tanner scale. Plasma cholesterol and triglyceride were quantitated each year; high, low, and very low density lipoprotein cholesterol (C-HDL, C-LDL, C-VLDL) levels were measured in the second and third years of the study. In males, cross-sectional decrements in plasma cholesterol were observed with increasing sexual maturation (Tanner stages 1–4), with an increment at Tanner 5 (sexual maturity); plasma triglyceride levels rose at all stages save Tanner 4. The mid-Tanner fall in plasma cholesterol appears (longitudinally) to be accounted for by reduction in C-HDL, while the rise in plasma cholesterol at Tanner 5 may be produced by an increase in C-LDL. Changes in age and Quetelet indices did not appear to relate closely to changes in C-VLDL in 12- and 13-yr-old males, but increasing age and Quetelet indices in 14–15-yr old males accompanied increasing C-VLDL. Cross-sectional studies in females revealed that plasma cholesterol fell at Tanner stages 3 and 4 and rose at stage 5; plasma triglyceride rose during all stages except Tanner 4. Longitudinal studies suggested that the decrements in plasma cholesterol in females may be partially accounted for by reductions in C-HDL; the increase in plasma cholesterol in late sexual development may be accounted for by an increase in C-LDL. In male children, we speculate that the fall in C-HDL and late rise in C-LDL as sexual maturation progresses is associated with increased testosterone production.

Plasma cholesterol and triglyceride levels in 6775 school children, ages 6–17

Associations of age, sex, and race with the distribution of fasting plasma cholesterol and triglyceride were studied in 6775 school children (4946 white and 1829 black students, ages 6–17 yr) in a biethnic school district. The target population included 8906 students with 84% of eligible white and 78% of eligible black children participating. In children ages 6–10, mean cholesterol and triglyceride levels varied only minimally. Females 6–10 yr old generally had higher mean plasma cholesterol and triglyceride than males, and blacks had higher mean cholesterol and lower mean triglyceride than whites, p < 0.001. In comparison to the cross-sectional stability of cholesterol and triglyceride over ages 6–10, plasma cholesterol began to fall at ages 11 and 12, continued to fall through ages 15–16, and rose at age 17. An inverse pattern was observed for mean triglycerides. The major increment in triglyceride levels occurred between the ages of 11 and 12, temporally concordant with decrements in cholesterol. Subsequently, in males mean triglycerides continued to rise through age 17, while in females mean triglycerides dipped sharply at ages 16 and 17. Withinrace comparisons of changes in triglyceride over age show the males first having lower triglyceride than females at ages 11–13, and the female levels falling below the male levels at ages 15–17. The decrements of cholesterol and increments in triglyceride during adolescence were also generally observed for the extremes of the distribution, the 5th and 95th percentiles. As was the case for 6–11-yr olds, in the 12–17-yr-old children, blacks had higher mean cholesterols and lower mean triglycerides than whites. Within the limitations of the cross-sectional nature of this study, the inverse changes of cholesterol and triglyceride suggest that hormonal and growth changes during adolescence may have a notable effect on plasma lipids. The availability of age-, sex-, and race-specific cholesterol and triglyceride distributions may allow more meaningful assessment of plasma cholesterol and triglyceride levels of any individual child.

Parent-offspring and sibling lipid and lipoprotein associations during and after sharing of household environments: the Princeton school district family study.

Abstract The specific aim of this report was to determine whether, and to what degree, parent-offspring and sibling associations for lipids and lipoproteins outlast the period of shared household environment. Intrafamilial lipid-lipoprotein associations were assessed in two and three generation kindreds in the Cincinnati Lipid Research Clinics Princeton School District Family Study. Intrafamilial lipid-lipoprotein associations were evaluated in parents and their pediatric (

Black-white differences in plasma lipids and lipoproteins in adults: The Cincinnati lipid research clinic population study☆

Black—white lipoprotein differences were studied in 43 pairs of adult males and 51 pairs of adult females to test the hypothesis that in a heterogeneous suburban biethnic setting, blacks have higher levels of high density lipoprotein cholesterol (C-HDL), lower levels of low density lipoprotein cholesterol (C-LDL), and lower levels of triglyceride (TG) when pair-matched by total plasma cholesterol, age, and sex with whites. With essentially identical total plasma cholesterol levels and comparable degrees of ponderosity, black males had lower plasma TG (P < 0.05) and higher plasma C-HDL levels (P < 0.005). There were no significant male black—white differences in C-LDL, but the ratio of C-LDL to C-HDL was lower in black males (P < 0.01). There were no significant differences in any lipoprotein fractions or the C-LDL/C-HDL ratio between black and white females, although black females had slightly lower plasma TG and slightly higher C-HDL than white females.

Cigarette smoking, alcohol intake, and oral contraceptives: Relationships to lipids and lipoproteins in adolescent school-children

The effects of cigarette smoking, alcohol intake, and oral contraceptives on plasma cholesterol, triglyceride, high density lipoprotein cholesterol (C-HDL), and low density lipoprotein cholesterol (C-LDL) were assessed in 965 12--19-year-old school-children in the Cincinnati Lipid Research Clinics Princeton school survey. After pair matching for age, sex, race, and total plasma cholesterol, adolescent children who smoked had mean C-HDL 6.1 mg/dl lower, and mean C-LDL 4.1 mg/dl higher, than nonsmokers (p less than 0.01). These findings for C-HDL were replicated by covariance analysis, adjusting for age, race, sex, alcohol intake, and triglyceride levels. Adolescents who drank alcohol had higher C-HDL and triglyceride levels and lower C-LDL than nondrinkers, but the differences were not significant. Adolescent females taking oral contraceptives had higher triglyceride, C-HDL, and C-LDL levels than matched controls, but the differences were not significant. If a portion of smokings contribution to coronary heart disease risk is mediated through its inverse association with C-HDL, and if smoking habits initiated in adolescence continue into adulthood, this report provides additional physiologic data relevant to programs designed to prevent, reduce, or stop cigarette smoking in the adolescent years.

The cincinnati lipid research clinic family study: Familial determinants of plasma uric acid

SummaryCommingling analysis of plasma uric acid levels in a random sample of 160 nuclear families supports the hypothesis that there is a mixture of three distributions. Assuming one, two, and three components in the underlying distribution, we obtained the corresponding p-values (for power transformation) as 0.059, 1.040, and 1.643, respectively. Path analysis with p=0.059 gives genetic (h2) and cultural (c2) heritabilities as 0.256 and 0.199, without much support for intergenerational differences, assortative mating, or maternal effects. Complex segregation analysis with p=0.059 supports multifactorial inheritance, consistent with the findings of Gulbrandsen et al. (1979) and Morton (1979) in other populations. This study also fails to support a major locus hypothesis, contrary to earlier reports.

High and low density lipoprotein cholesterol levels in hypercholesterolemic school children.

To most fully explicate risk to coronary heart disease (CHD) in adults and children with elevated plasma total cholesterol, the levels of high and low density lipoprotein cholesterol (C-HDL, C-LDL) must be quantitated. This report focuses upon C-HDL and C-LDL levels in children identified in a lipid and lipoprotein sampling survey of 6,775 Princeton School children, by either total plasma cholesterol ≥205 mg/dl, the approximate 95th percentile for children 6–17 years of age, or age-, sex-, and race-specific 95th percentiles for cholesterol. Using the sex-, race-specific local 95th percentiles for C-HDL and C-LDL, the hypercholesterolemic children were separated into four categories according to whether they had elevations of both C-HDL and C-LDL, C-HDL only, C-LDL only, or neither. When selection for hypercholesterolemia was based on the overall 95th percentile (205 mg/dl), black children were more likely than white to have elevations of C-HDL only, which accounted for their hypercholesterolemia, p<.05, whereas white children were much more likely to have elevations of C-LDL only, than were black children, p<.005. However, when selection for hypercholesterolemia was based on age-, sex-, and race-specific 95th percentile cholesterol levels, there were no differences in the proportion of black and white children having elevations of C-HDL and C-LDL, accounting for their hypercholesterolemia. Elevated levels of C-HDL can explain apparent hypercholesterolemia in at least 16% of children, ages 6–17, who may putatively be at reduced, rather than increased CHD risk.

Clustering and interrelationships of high-, low-, and very low-density lipoproteins in randomly recalled children and adults: the Cincinnati Lipid Research Clinic's Princeton School Prevalence Study.

Abstract The aim of this study, encompassing 146 children and 42 adults having total plasma cholesterol, triglyceride, or both (less than or the same as) age-, sex-, and race-specific 5th percentile levels, was to better define the interrelationships of low-, high-, and very low-density lipoprotein cholesterols (C-LDL, C-HDL, C-VLDL) within hypolipidemic individuals, using multivariate cluster analysis. For both children and adults, the C-LDL distribution was gaussian; the C-HDL and C-VLDL distributions were skewed to the right. The C-HDL and C-VLDL distributions were unimodal and gaussian after square root and log transformations, respectively. After consolidation of lipoprotein clusters in both children and adults into six groups by virtue of C-LDL, C-HDL, and C-VLDL in three dimensions, a numerical majority of both children (75%) and adults (95%) had predominant hypobetalipoproteinemia accounting for their hypocholesterolemia. This hypobetalipoproteinemia was accompanied by C-HDL in the 50th percentile or higher in 80% of children and in 93% of adults. Moreover, there were a nontrivial number of both children and adults having the combination of exceptionally low C-LDL and high C-HDL levels. There were few to no major cluster groups characterized by simultaneous depressions of all three lipoproteins, and only a modest number characterized by depression of both C-LDL and C-HDL with high C-VLDL. In view of the positive and negative associations of C-LDL and C-HDL, respectively, with coronary heart disease events, a majority of hypolipidemic subjects may putatively be at sharply reduced risk for development of atherosclerosis.

Interrelationships of lipids, lipoproteins, and clinical chemistry measurements in 1605 schoolchildren, ages 6–17: The princeton schoolchildren study

Interrelationships between clinical chemistry tests (hepatic, renal, and endocrine systems) and lipids-lipoproteins were assessed in 1605 schoolchildren ages 6-17; 916 were randomly selected and 689 selected because of hypercholesterolemia/hypertriglyceridemia from the Cincinnati Lipid Research Clinics Princeton School study. The clinical chemistry measurements most consistently and uniformly rated to lipids and lipoproteins were plasma glucose (GLU), uric acid (UA), serum glutamic oxaloacetic transaminase (SGOT) and hematocrit (HEMO). These relationships were similar quantitatively and qualitatively in 6-11-yr-old and 12-17-yr-old children in both the random and the hyperlipidemic recall groups. The most consistent relationship was a positive one between glucose and triglyceride (TG) and very low density lipoprotein cholesterol (C-VLDL). A second, highly consistent, relationship pattern included an inverse correlation between serum UA and high density lipoprotein cholesterol (C-HDL)), and a positive UA-C-VLDL relationship; both were seen in 12-17-yr-old children. Hematocrit was positively associated with TG; SGOT was positively associated with total cholesterol and C-HDL. Many of these relationships, particularly those for plasma GLU and UA, presage relationships observed in normal and hyperlipoproteinemic adults, and may allow a better understanding of the physiology and pathophysiology of lipid and lipoprotein levels.