The levels of lead, cadmium, and mercury in the blood were log-transformed because their distributions were positively skewed, and the un-weighted and weighted geometric means (GM) with 95% confidence intervals (CI) were calculated by gender using the Proc Descript function in SUDAAN.
Odds ratios (ORs) and 95% CI for hypertension and prehypertension were calculated for log-transformed blood lead, cadmium, and mercury (base 2) levels as a continuous variable after covariate adjustment using Proc Rlogist with un-weighted and weighted statistical procedures. Covariates were gender, age, residence area, education level, smoking and drinking status, hemoglobin, body mass index, and serum creatinine.
Finally, the ORs and 95% CI values for osteoporosis were calculated for log-transformed blood lead, cadmium, and mercury (base 2) levels as continuous variables and quartiles of blood mercury in postmenopausal women after covariate adjustment using Proc Rlogist with un-weighted ordinary statistical data analyses and design-based weighted statistical procedures.