Amirahmad Nejat1, Mohammadhassan Mirbolouk1, Reza Mohebi1, Mitra Hasheminia1, Maryam Tohidi1, Navid Saadat1, Fereidoun Azizi2, Farzad Hadaegh3. 1. Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran. 2. Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran. 3. Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran. Electronic address: fzhadaegh@endocrine.ac.ir.
Abstract
BACKGROUND: Data on the impact of changes in lipid measures on subsequent coronary heart disease (CHD) outcomes are not consistent. METHODS: Study was conducted in 4459 adults, aged ≥30 years, free of cardiovascular disease at baseline who attended two consecutive examinations first in 1999-2001 and second in 2001-2003, and were followed up until March 31, 2010. Multivariate Cox proportional hazard regression adjusted for baseline lipid measures and other risk factors was calculated for a 1 standard deviation (SD) change in total cholesterol (TC), log-transformed triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) (calculated using modified Friedewald formula), non-HDL-C, TC/HDL-C and log-transformed TG/HDL-C. Effect of change in dyslipidemia (TC ≥6.21 mmol/L or TG ≥2.26 mmol/L or HDL-C <1.03 mmol/L or non-HDL-C ≥4.91 mmol/L) on incident CHD was examined, considering those with no dyslipidemia at baseline and follow-up as the reference group. RESULTS: During a mean follow-up of 9.5 years, 303 cases of CHD occurred. A 1-SD increase in TC, TG, non-HDL-C, TC/HDL-C and TG/HDL-C was associated with 14, 20, 19, 16 and 14% increase in risk of CHD event, respectively (all p values <0.05); the corresponding risk for LDL-C was [1.12 (0.99-1.27), P=0.07]. Participants with maintained dyslipidemia during follow-up had a significant risk for incident CHD [HR: 1.67(1.21-2.49)] compared to those with no dyslipidemia at baseline or follow-up. CONCLUSION: Changes in TC, TG, and non-HDL-C, TC/HDL-C, TG/HDL-C were independent predictors of CHD events. Furthermore, maintained dyslipidemia was a strong predictor for CHD events.
BACKGROUND: Data on the impact of changes in lipid measures on subsequent coronary heart disease (CHD) outcomes are not consistent. METHODS: Study was conducted in 4459 adults, aged ≥30 years, free of cardiovascular disease at baseline who attended two consecutive examinations first in 1999-2001 and second in 2001-2003, and were followed up until March 31, 2010. Multivariate Cox proportional hazard regression adjusted for baseline lipid measures and other risk factors was calculated for a 1 standard deviation (SD) change in total cholesterol (TC), log-transformed triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) (calculated using modified Friedewald formula), non-HDL-C, TC/HDL-C and log-transformed TG/HDL-C. Effect of change in dyslipidemia (TC ≥6.21 mmol/L or TG ≥2.26 mmol/L or HDL-C <1.03 mmol/L or non-HDL-C ≥4.91 mmol/L) on incident CHD was examined, considering those with no dyslipidemia at baseline and follow-up as the reference group. RESULTS: During a mean follow-up of 9.5 years, 303 cases of CHD occurred. A 1-SD increase in TC, TG, non-HDL-C, TC/HDL-C and TG/HDL-C was associated with 14, 20, 19, 16 and 14% increase in risk of CHD event, respectively (all p values <0.05); the corresponding risk for LDL-C was [1.12 (0.99-1.27), P=0.07]. Participants with maintained dyslipidemia during follow-up had a significant risk for incident CHD [HR: 1.67(1.21-2.49)] compared to those with no dyslipidemia at baseline or follow-up. CONCLUSION: Changes in TC, TG, and non-HDL-C, TC/HDL-C, TG/HDL-C were independent predictors of CHD events. Furthermore, maintained dyslipidemia was a strong predictor for CHD events.