A simple nomogram for determination of echocardiographic left ventricular geometry

Mild renal insufficiency is associated with increased left ventricular mass in men, but not in women: An arterial stiffness-related phenomenon—The Hoorn Study

BACKGROUND

Mild renal insufficiency has recently been recognized as an important risk factor for cardiovascular disease (CVD). The mechanisms underlying this association are incompletely understood. Increased left ventricular mass (LVM) is an independent risk factor for CVD, which is particularly common in end-stage renal disease (ESRD) and which has been shown to be associated with mild renal insufficiency. Increased arterial stiffness has also been shown to be an independent risk factor for CVD in ESRD and has also been associated with mild renal insufficiency. We hypothesized that the association between mild renal insufficiency and increased LVM could be mediated through increased arterial stiffness, and that this may be one of the pathways linking mild renal insufficiency to CVD. We therefore investigated, in a cross-sectional population-based study, the influence of increased arterial stiffness on the association between renal function and LVM.

METHODS

The study population consisted of 742 elderly individuals (373 men and 369 women). Renal function was estimated by the serum creatinine level in micromol/L; by the Cockcroft-Gault formula in mL/min and by the Modification of Diet in Renal Disease (MDRD) formula. LVM was obtained by echocardiography.

RESULTS

The mean estimates of renal function in men and women were, respectively, 103.7 (SD 17.0) and 86.8 (SD 11.2) micromol/L for the serum creatinine level; 63.4 (SD 12.9) and 61.4 (SD 11.0) mL/min/1.73 m(2) for the Cockcroft-Gault formula; and 59.7 (SD 10.8) and 60.9 (SD 10.5) mL/min per 1.73 m(2) for the MDRD formula. LVM was 93.1 (SD 26.4) g/m(2) in men and 86.7 (SD 22.3) g/m(2) in women. In men, impaired renal function, as estimated by the Cockcroft-Gault and the MDRD formula, was significantly associated with greater LVM after adjustment for age, glucose tolerance, hypertension, and prior CVD [regression coefficient beta (95% CI), 1.28 (0.22 to 2.33) g/m(2) and 1.63 (0.41 to 2.86) g/m(2) per 5 mL/min/1.73 m(2) decrease, respectively]. However, the association between impaired renal function and increased LVM was not statistically significant after adjustment for arterial stiffness estimates [regression coefficient beta (95% CI), 0.02 (-1.60 to 1.64) g/m(2) and 0.54 (-1.25 to 2.33) g/m(2) per 5 mL/min/1.73 m(2) decrease, respectively]. In women, impaired renal function was not significantly associated with greater LVM.

CONCLUSION

Our study shows that in a general elderly population, even mild impairment of renal function is associated with adverse changes in left ventricular structure. In men, but not in women, this leads to greater LVM, a process that may be related to increases in arterial stiffness. Importantly, these novel findings suggest that such changes occur early in the process of renal functional deterioration, which may explain, in part, the increase in cardiovascular risk in men with mildly impaired renal function.

Left ventricular mass increases with deteriorating glucose tolerance, especially in women: independence of increased arterial stiffness or decreased flow-mediated dilation: the Hoorn study

OBJECTIVE

Type 2 diabetes and impaired glucose metabolism (IGM) are associated with an increased cardiovascular disease (CVD) risk. Increased left ventricular mass (LVM) is thought to increase CVD risk through several unfavorable cardiac changes. Type 2 diabetes and IGM are associated with increased LVM, but the underlying mechanism is unclear. We investigated the association between glucose tolerance status (GTS) and LVM and explored whether any such association could be mediated through increased arterial stiffness, impaired endothelial function, or the presence of atherosclerosis.

RESEARCH DESIGN AND METHODS

We used ultrasound to measure LVM, carotid and femoral stiffness, carotid-femoral transit time, and flow-mediated vasodilation (FMD) and tonometry to estimate compliance and augmentation index. The study population (n = 780) consisted of 287 individuals with normal glucose metabolism (NGM), 179 with IGM, and 314 with type 2 diabetes, and the mean age was 68.4 years.

RESULTS

In women, after adjusting for age, height, BMI, and mean arterial pressure, LVM increased significantly with deteriorating GTS (LVM 157 g in NGM, 155 g in IGM, and 169 g in type 2 diabetes; P for trend <0.018). Additional adjustment for arterial stiffness, FMD, or the presence of atherosclerosis did not materially alter the results, even though these variables were significantly associated with both GTS and LVM. Indexes of hyperglycemia/-insulinemia or insulin resistance explained at most 7% of the association between GTS and LVM. In men, no statistically significant associations were observed.

CONCLUSIONS

Our data expand the conceptual view of the pathogenesis of GTS-related changes in LVM because we show that the increase in LVM in women is independent of increased arterial stiffness, impaired FMD, or the presence of atherosclerosis. In addition, we show that this increase in LVM is only minimally explained by indexes of hyperglycemia/-insulinemia or insulin resistance. Our data may, in part, explain the increased CVD risk seen in women with deteriorating GTS.

Left ventricular mass index increase in early renal disease: impact of decline in hemoglobin

Cardiovascular disease occurs in patients with progressive renal disease both before and after the initiation of dialysis. Left ventricular hypertrophy (LVH) is an independent predictor of morbidity and mortality in dialysis populations and is common in the renal insufficiency population. LVH is associated with numerous modifiable risk factors, but little is known about LV growth (LVG) in mild-to-moderate renal insufficiency. This prospective multicenter Canadian cohort study identifies factors associated with LVG, measured using two-dimensional-targeted M-mode echocardiography. Eight centers enrolled 446 patients, 318 of whom had protocol-mandated clinical, laboratory, and echocardiographic measurements recorded. We report 246 patients with assessable echocardiograms at both baseline and 12 months with an overall prevalence of LVH of 36%. LV mass index (LVMI) increased significantly (>20% of baseline or >20 g/m2) from baseline to 12 months in 25% of the population. Other than baseline LVMI, no differences in baseline variables were noted between patients with and without LVG. However, there were significant differences in decline of Hgb level (-0.854 v -0.108 g/dL; P = 0.0001) and change in systolic blood pressure (+6.50 v -1.09 mm Hg; P = 0.03) between the groups with and without LVG. Multivariate analysis showed the independent contribution of decrease in Hgb level (odds ratio [OR], 1.32 for each 0.5-g/dL decrease; P = 0.004), increase in systolic blood pressure (OR, 1.11 for each 5-mm Hg increase; P = 0.01), and lower baseline LVMI (OR, 0.85 for each 10-g/m2; P = 0.011) in predicting LVG. Thus, after adjusting for baseline LVMI, Hgb level and systolic blood pressure remain independently important predictors of LVG. We defined the important modifiable risk factors. There remains a critical need to establish optimal therapeutic strategies and targets to improve clinical outcomes.