First-Degree Kinship with Young Coronary Artery Disease Patients Markedly Increases Lipid-Level Disorders in Asymptomatic Hypertensives

Abstract

Background Association of hypertension and serum lipid disorders has been demonstrated in previous studies. However, there are no investigations about the behaviour of serum lipids in asymptomatic hypertensive individuals who are first degree relatives of young coronary patients.

Objective To determine the degree of lipid disorders in Brazilian hypertensive individuals who are first degree relatives of young coronary patients.

Methods There were four study groups, 2 in each arm of the study: A) 846 subjects without any evidence of heart disease or diabetes who were first degree relatives of patients who underwent coronary artery bypass grafting (CABG) surgery before 55 years-of-age. Of these subjects, 226 individuals were hypertensive (group Hyp F), and 620 were normotensive (group Normo F): B) 910 hospital employees without evidence of cardiovascular disease and family history of coronary artery disease of whom 152 were hypertensive (group Hyp NF), and 758 were normotensive (group Normo NF). Hypertension was defined as blood pressure greater than 140/90 mmHg. The following serum lipid measurements were performed: Total cholesterol, high-density lipoprotein cholesterol (HDLC), low-density lipoprtein cholesterol (LDLC), and triglycerides. Lipid disorders were defined according to the 2^nd Report of the National Cholesterol Education Program (NCEP) (total cholesterol >240 mg/dl; LDL0160 mg/dl; triglycerides > 200mg/dl). The frequency of lipid disorders in each group was calculated. Subjects were classified according to their body mass index (BMI) as normal, overweight, or obese. The following statistical analyses were performed as indicated: ANOVA (with Tukey's corrections for multiple comparisons), chi-square (χ²), and odds ratio (OR).

Results Hyp F subjects had significantly higher total cholesterol, LDLC and triglyceride levels, and significantly lower levels of HDLC than all other groups. There was a higher frequency of lipid disorders in Hyp F subjects than in Hyp NF individuals, with a significant OR of 1.71 (Cl 1.26-2.32) and 2.09 (Cl 1.48-2.72) for total cholesterol and LDLC respectively. When compared to Normo F subjects, Hyp F individuals had significantly higher risk of having lipid disorders: Total cholesterol (OR = 8), LDLC (OR = 6), and triglycerides (OR = 5). There was a higher frequency of obesity among Hyp F patients than in all other groups. The frequency of subjects who were overweight or obese was higher in Hyp F than in Hyp NF subjects.

Conclusion Hypertensive patients who were first degree relatives of patients revascularized at a young age had a higher prevalence of lipid disorders, particularly higher total cholesterol and LDLC, than hypertensive individuals without this family history. These individuals may have a greater genetic propensity to develop lipid disorders.