Introduction to results on Seasonal Changes in Cholesterol

This report summarizes results relative to seasonal changes in cholesterol, and provides alternative results to a report based on winter-summer differences in cholesterol (sea01d01.doc). We report descriptive data on the subjects in the seasonal cholesterol study by gender, and within gender, by age (< 50 or 50+). We also include results for variables corresponding to BMI, waist, hip and waist:hip ratio measures. Hip and waist measures were made at the start and end of the study (quarters 1 and 5). BMI measures were made each quarter. The results presented here are based on a different subset of study subjects than the results presented in sea01d01.doc. In the document sea01d01.doc, only n=478 subjects were included, representing all subjects with at least one summer and one winter cholesterol measure and at least 4 or more cholesterol measures. Summer and winter are defined using the ‘common season’ definition (winter=Dec 21-March 20; summer=June 21-Sept. 20). In this document, we present results on a basic subset of n=517 subjects, all of whom have 4 or more cholesterol measures. In addition, we compare this subset of subjects with the basic seasons subjects (n=641) and the more limited set of subjects (n=478) that include a minimum of one summer and one winter measure. For all analyses considered here, we excluded data for ID=77, quarter=5 due to an apparent error in ID coding.