Serum cholesterol concentrations among Navajo Indians

Area of Science:

• Cardiovascular Health
• Nutritional Epidemiology
• Indigenous Health

Background:

• Previous studies indicated low serum lipid concentrations and hyperlipidemia prevalence among Navajo Indians.
• A significant data gap existed for over two decades regarding serum lipid levels in this population.
• Low rates of ischemic heart disease were historically associated with Navajo populations.

Purpose of the Study:

• To determine the distribution of serum lipid concentrations (total cholesterol, HDL, LDL, triglycerides) in a representative Navajo community.
• To compare these lipid concentrations with national data from the second National Health and Nutrition Examination Survey (NHANES II).
• To assess potential shifts in cardiovascular risk factors within the Navajo population.

Main Methods:

• Cross-sectional study of 255 Navajo individuals (105 men, 150 women) aged 25-74 years.
• Analysis of serum total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglyceride concentrations.
• Comparison of Navajo data against NHANES II data for the general US population.

Main Results:

• Navajo men showed similar TC concentrations to NHANES II men.
• Navajo women under 55 had similar TC to younger NHANES II women, but older Navajo women had significantly lower TC.
• Elevated TC (>240 mg/dL) was found in 33.8% of Navajo men, exceeding NHANES II rates, while Navajo women had lower prevalence (17.5%) than NHANES II women (32.9%).
• A similar pattern of elevated lipids was observed for low-density lipoprotein cholesterol.

Conclusions:

• Navajo Indians no longer exhibit uniformly low serum lipid concentrations.
• Increased cholesterol levels may indicate a rising prevalence of atherosclerotic coronary heart disease.
• Primary prevention of hyperlipidemia in Navajo Indian communities requires focused attention.