Lipids, lipoproteins, lifestyle, adiposity and fat-free mass during middle age: the Fels Longitudinal Study.
BACKGROUND
Although lipid profiles tend to worsen with age, it is not fully known if such age-related changes are influenced primarily by body composition and lifestyle or by other aspects of aging.


OBJECTIVE
We investigated the extent to which the fat and fat-free components of body mass index (BMI) and lifestyle factors influence patterns of change in lipids independent of age.


METHODS
Serial data were analyzed using sex-specific longitudinal models. These models use serial data from individuals to assume a general pattern of change over time, while allowing baseline age and the rate of change to vary among individuals.


METHODS
Serial data were obtained from 940 examinations of 269 healthy white participants (126 men, 143 women), aged 40-60 years, in the Fels Longitudinal Study.


METHODS
Measurements included age, the fat (FMI) and fat-free mass (FFMI) components of BMI, high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), triglycerides (TG), total cholesterol (TC), fasting glucose and insulin, physical activity, alcohol use and smoking, and women's menopausal status and estrogen use.


RESULTS
In both sexes, increased FMI was significantly associated with increased LDL-C, TG and TC, and decreased HDL-C. Increased FFMI was significantly related to decreased HDL-C and increased TG. Independent age effects remained significant only for LDL-C and TC in men and TC in women. Increased insulin was significantly related to increased TG in women. Moderate alcohol consumption was associated with higher HDL-C in men. Physical activity lowered male LDL-C and TC levels, and increased female HDL-C levels. Menopause was associated with increases in LDL-C. Premenopausal women not using estrogen had significantly lower HDL-C, TG, and TC than postmenopausal women taking estrogen.


CONCLUSIONS
(1) Age is an important independent predictor for LDL-C and TC in men, and TC in women, but it is not as influential as body composition and lifestyle on HDL-C and TG in men and women, and LDL-C in women. (2) Increasing FMI is the major contributor to elevated TC, LDL-C and TG levels, and decreased HDL-C levels in men and women. (3) FFMI significantly influences HDL and TG levels in both sexes. (4) Maintaining a lower BMI via a reduced fat component may be more beneficial in lowering CVD risks than other factors.
Schubert
C M
CM
Lifespan Health Research Center, Department of Community Health, Wright State University School of Medicine, Dayton, OH 45420, USA. christine.schubert@wright.edu
Rogers
N L
NL
Remsberg
K E
KE
Sun
S S
SS
Chumlea
W C
WC
Demerath
E W
EW
Czerwinski
S A
SA
Towne
B
B
Siervogel
R M
RM
D000328:Adult; D000375:Aging; D000428:Alcohol Drinking; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition; D015992:Body Mass Index; D002784:Cholesterol / Q000097:blood; D015914:Estrogen Replacement Therapy; D005260:Female; D006306:Health Surveys; D006801:Humans; D007328:Insulin / Q000097:blood; D008019:Life Style; D008055:Lipids / Q000097:blood*; D008074:Lipoproteins / Q000097:blood*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D012737:Sex Factors; D012907:Smoking; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D007328:Insulin; D008055:Lipids; D008074:Lipoproteins; D014280:Triglycerides; D002784:Cholesterol