Purpose: The purpose of this manuscript is to examine changes in blood lipid levels and related factors between 1983 and 1987 in two selected Polish populations, to evaluate these changes and their association with other coronary heart disease (CHD) risk factors, and to examine the nutrient intake changes for consistency with observed lipid changes.
Methods: Men and women, aged 35-64 were screened from Warsaw and rural Tarnobrzeg province, Poland-the Pol-MONICA screening sites. An independent random sample of 5132 screened in 1983-84 and a second independent random sample of 2596 screened in 1987-88 were compared. A 25% cohort of the 1983-84 sample was also rescreened in 1987-88 (n = 1236) and 24-hour dietary recall information on this cohort was used to evaluate nutrient intake changes and their relationship to the lipid changes.
Results: For the random samples, the total cholesterol increased by 5.1 mg/dL (rural) and by 7.9 mg/dL (urban) for women; there were no significant changes among men. Low-density lipoprotein cholesterol (LDL-C) increased for all site and gender subgroups by 5.4-8.7 mg/dL. Among rural men and women, high-density lipoprotein cholesterol (HDL-C) decreased by 3.4 and 3.3 mg/dL, respectively, whereas it increased by 3.3 mg/dL among urban women and did not change among urban men. Total triglycerides (TG) increased by 9.5 mg/dL for rural men, with no significant change for rural women. For urban men and women, TG decreased by 29.5 and 21.8 mg/dL respectively. In the cohort, changes in dietary intake (decreases in energy from fat, Keys index and increases in the polyunsaturated to saturated fats ratio) were related to a decrease in TC at both sites and to a decrease or smaller increase in LDL-C for rural men.
Conclusions: The observed changes were generally unfavorable, with a decrease in the proportion of persons with desirable lipid levels. At both sites nutritional changes were favorable, including a drop in total energy intake. Less pronounced were changes in percentages of total energy from fats, where the only significant decrease was for rural women; however, improvements in dietary fat composition and declines in cholesterol consumption were found. These favorable changes in diet were not strong enough or were not in effect long enough to counter the unfavorable changes in blood lipids.