Factors associated with changes in serum total cholesterol levels over 7 years in middle-aged New Zealand men and women: a prospective study.
OBJECTIVE
The aim of this study was to determine the factors associated with changes in serum total cholesterol levels over a period of seven years.


RESULTS
The baseline Workforce Diabetes Survey was carried out between 1988 and 1990 and involved workers predominantly aged > or = 40 years; a follow-up survey of 4,053 participants was carried out between 1995 and 1997. Both surveys measured serum lipid levels by means of enzymatic methods. The overall age- and gender-adjusted mean serum cholesterol levels decreased by 4.6% between the two surveys. The two-thirds of participants who experienced a decrease in total serum cholesterol formed a higher risk group at baseline insofar as they were older, more inactive and more likely to be male, and had higher blood pressure (BP), higher serum cholesterol and triglyceride levels, and a higher body mass index (BMI) and waist/hip ratio than the one-third whose serum cholesterol levels increased (all p < 0.05). The decrease in serum cholesterol was associated with improvements or less deterioration in risk factors (fasting glucose, BP, BMI and the waist/hip ratio, the low-density/high-density lipoprotein (LDL/HDL) ratio, triglyceride concentrations and level of physical activity) and an increase in the use of lipid lowering drugs.


CONCLUSIONS
Serum cholesterol levels decreased over the seven years between the surveys, principally among the individuals at highest risk. The use of lipid lowering drugs contributed to this decline but lifestyle factors, such as increased exercise levels, may also have played a role because other risk factors also improved.
Metcalf
P A
PA
Department of Statistics, School of Medicine, University of Auckland, Private Bag 92019, Auckland 1, New Zealand. p.metcalf@auckland.ac.nz
Scragg
R K
RK
Swinburn
B A
BA
Shaw
L M
LM
D000328:Adult; D000368:Aged; D001824:Body Constitution / Q000502:physiology; D002784:Cholesterol / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D006306:Health Surveys; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood / Q000188:drug therapy / Q000453:epidemiology*; D000960:Hypolipidemic Agents / Q000627:therapeutic use*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009520:New Zealand / Q000453:epidemiology; D011446:Prospective Studies; D012307:Risk Factors; D014280:Triglycerides / Q000097:blood*
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D000960:Hypolipidemic Agents; D014280:Triglycerides; D002784:Cholesterol