Elevated Brachial-Ankle Pulse Wave Velocity is independently associated with Microalbuminuria in a rural population

Abstract

Objectives

Microalbuminuria is used to a predictor for cardiovascular morbidity and mortality due to cardiovascular diseases. Also, microalbuminuria is a marker of generalized endothelial dysfunction resulting from arterial stiffness or insulin resistance. However, the mechanism of microalbuminuria is unclear. Therefore, it is important to evaluate the relationship between arterial stiffness or insulin resistance and microalbuminuria. Meanwhile, brachial-ankle pulse wave velocity (baPWV) is a good measure of arterial stiffness. Thus, baPWV is a useful measure for explain the relationship between arterial stiffness and microalbuminuria. This study aimed to investigate whether elevated baPWV is independently associated with microalbuminuria.

Methods

This study included 1,648 individuals aged over 40 who participated in baseline Multi-Rural Cohort Study conducted in Korean rural communities between 2005 and 2006. The participants were classified into: less than 30mg/g as normoalbuminuria or 30-300mg/g as microalbuminuria using urinary albumin creatinine ratio (UACR). BaPWV data were transformed to a normal distribution using natural logarithms to improve normality. Multivariate logistic regression analyses were performed to determine associations with baPWV and microalbuminuria and odds ratios were calculated.

Results

The median and Q1-Q3 baPWV values were significantly higher in the microalbuminuric group both in men (1538, 1370-1777 cm/s vs. 1776, 1552-2027 cm/s, p<0.001) and in women (1461, 1271-1687cm/s vs. 1645, 1473-1915cm/s, p<0.001). Five models were used to estimate the relation between baPWV and microalbuminuria. The baPWV was independently associated with microalbuminuria in both genders after adjusting for heart rate, fasting blood glucose, triglyceride, homeostatic model assessment insulin resistance and history of hypertension and diabetes. Fasting blood sugar and HOMAIR were judged they had nothing to do with multicolinearity (r=0.532, p<0.001). Log(baPWV) (OR

15.813, 95%CI

2.629-95.119) was the only independent risk factor in men, while log(baPWV) (OR

5.399, 95%CI

1.157-25.205) and fasting blood glucose (OR

1.011, 95%CI

1.002-1.020) were significant in women by adjusting for all significant variables in the univariate analyses.

Conclusion

BaPWV was the only factor examined that was independently associated with microalbuminuria in both genders and in all the models examined. Elevated baPWV is independently associated with microalbuminuria regardless of insulin resistance among rural subjects over 40 yr. However, baPWV cant be a very good indicator considering relatively low explanatory power representing for adjusted R2 value. It means that many factors contribute to microalbuminuria except baPWV as well as other factors used this study. However, in consideration of not only the ease of the measurement of baPWV but results of this study, it may be a useful screening tool for predicting cardiovascular complications.