Association of Serum Lipids with 10-Year CVD and All-Cause Mortality in Iranian Adults: A Prospective Cohort Study.

Higher HDL-C tertiles were associated with significantly lower risk of all-cause mortality compared to the lowest tertile after full adjustment.

• Second tertile of HDL-C (37.9–45.8 mg/dL): HR=0.72, 95% CI: 0.57–0.92 for all-cause mortality
• Third tertile of HDL-C (45.8–96.2 mg/dL): HR=0.81, 95% CI: 0.64–1.03 for all-cause mortality
• Lowest tertile (≤37.9 mg/dL) served as the reference group
• Model 3 was adjusted for BMI, smoking status, diabetes, hypertension, CVD, job, marital status, education level, and lipid-lowering drug use

Individuals in the second HDL-C tertile had a significantly reduced risk of cardiovascular mortality after full adjustment.

• Second tertile of HDL-C: HR=0.66, 95% CI: 0.46–0.94 for cardiovascular mortality
• The third tertile did not reach statistical significance for cardiovascular mortality
• This association was observed in a cohort of 9704 participants followed for approximately 10 years

No significant associations were found between LDL-C and mortality after multivariable adjustment.

• LDL-C was analyzed both as a continuous variable and categorized into tertiles
• Adjustment included age, sex, BMI, smoking, diabetes, hypertension, CVD, job, marital status, education level, and lipid-lowering drug use
• This finding applied to both all-cause mortality and cardiovascular mortality outcomes

Kaplan-Meier analyses confirmed significant survival differences across tertiles of HDL-C, TG, and non-HDL-C for all-cause mortality.

• HDL-C tertiles: P value = 0.005 for all-cause mortality
• TG tertiles: P value = 0.001 for all-cause mortality
• Non-HDL-C tertiles: P value < 0.001 for all-cause mortality
• HDL-C survival curves also differed significantly for cancer mortality (P value = 0.048)

Kaplan-Meier analyses showed significant differences in cardiovascular death survival curves for HDL-C and TG groups.

• HDL-C groups: P value = 0.003 for cardiovascular mortality
• TG groups: P value = 0.015 for cardiovascular mortality
• Over the 10-year follow-up, there were 185 cases of CVD death out of 429 total deaths (4.4% of the cohort)

The inverse correlation between elevated HDL-C levels and mortality was more pronounced in older individuals and those with hypertension or diabetes.

• Subgroup analyses were performed to evaluate confounding variables related to serum lipid levels and mortality
• The association was less significant in younger and healthier individuals
• These patterns were described as 'substantially greater' in older participants and those with comorbidities

The study cohort consisted of 9704 individuals aged 35–65 years from the MASHAD study, followed for approximately 10 years.

• The MASHAD (Mashhad Stroke and Heart Atherosclerotic Disorder) study was initiated in 2007
• Over the follow-up period, there were 429 deaths (4.4%), including 185 CVD deaths and 124 cancer deaths
• Multivariable Cox proportional hazards models were applied with three adjustment levels
• Lipid variables (LDL-C, HDL-C, non-HDL-C, TG) were analyzed as continuous variables and in tertiles