Association between serum aluminum levels and cardiothoracic ratio in patients on chronic hemodialysis

<div><p>The cardiothoracic ratio (CTR) and serum aluminum levels are both associated with mortality in hemodialysis patients. However, limited data regarding the association between serum aluminum levels and the CTR have been published to date. Therefore, we aimed to elucidate this association in patients on chronic hemodialysis (CHD). We investigated the association between the serum aluminum level and the CTR in CHD in a retrospective cross-sectional study of 547 Taiwanese patients on CHD. The mean age of patients was 62.5±13.2 years, with a mean hemodialysis time of 7.1±5.2 years. Among the patients, 36.9% were diabetic and 47.9% were male. After natural logarithmic transformation (ln(aluminum)), the serum aluminum level exhibited an independent and linear relationship with the CTR (β: 1.40, 95% confidence interval (CI), 0.6–2.2). A high serum aluminum level (≥6 ng/dL) was significantly associated with a CTR >0.5 in the crude analysis (odds ratio (OR): 2.15, 95% CI, 1.52–3.04) and remained significant after multivariable adjustment (OR: 2.45, 95% CI, 1.63–3.67). Moreover, the ln(aluminum) value was significantly associated with a CTR >0.5 (OR: 1.71, 95%CI, 1.28–2.29) in multivariable analysis, indicating a dose effect of aluminum on cardiomegaly. In conclusion, the serum aluminum level was independently associated with cardiac remodeling (elevated CTR) in patients on CHD.</p></div

Distribution of serum aluminum levels in patients on chronic hemodialysis.

<p>Distribution of serum aluminum levels in patients on chronic hemodialysis.</p

Logistic regression analysis of risk factors for cardiomegaly (CTR >0.5) in patients on chronic hemodialysis.

<p>Logistic regression analysis of risk factors for cardiomegaly (CTR >0.5) in patients on chronic hemodialysis.</p

Regression plot of cardiothoracic ratios (%) with serum aluminum levels after natural log transformation (ln(aluminum)).

<p>Lines indicate best-fit regression lines derived from the least mean square method.</p

Association between serum aluminum levels and cardiothoracic ratio in patients on chronic hemodialysis - Fig 4

<p><b>Subgroup analysis of the association between a cardiothoracic ratio >0.5 and (a) the serum aluminum level with a cut-off value of 6 ng/dL; and (b) the serum aluminum level after natural log transformation (ln(aluminum))</b>. The full model comprised adjusted variables, including age, gender, hemodialysis vintage, diabetes mellitus, cardiovascular disease, smoking history, systolic blood pressure, diastolic blood pressure, body mass index, albumin, hemoglobin, transferrin saturation, ionized calcium, and phosphate levels.</p

Characteristics of the study population.

<p>Characteristics of the study population.</p

Characteristics of study population.

<p>Abbreviations: CVD, cardiovascular disease; BP, blood pressure; iPTH, intact parathyroid hormone; Ca, calcium; P, phosphate; ABI, ankle-brachial index; RAS, renin-angiotensin system.</p><p>Characteristics of study population.</p

Cox proportional hazards regression analysis for all-cause mortality.

<p>Abbreviation: CVD, cardiovascular disease; BP, blood pressure; RAS, renin-angiotensin system; iPTH, intact parathyroid hormone; Ca, calcium; P, phosphate; PAOD, peripheral arterial occlusion disease.</p><p>Cox proportional hazards regression analysis for all-cause mortality.</p

Cox proportional hazards regression analysis for cardiovascular mortality.

<p>Abbreviation: CVD, cardiovascular disease; BP, blood pressure; RAS, renin-angiotensin system; PAOD, iPTH, intact parathyroid hormone; Ca, calcium; P, phosphate; peripheral arterial occlusion disease.</p><p>Cox proportional hazards regression analysis for cardiovascular mortality.</p

Probabilities of overall survival according to dominance side of ABI value.

<p>(A) in all patients with log-rank test: χ² = 1.32; <i>P</i> = 0.249; (B) in patients without PAOD with log-rank test: χ² = 3.47; <i>P</i> = 0.062; (C) in patients with PAOD with log-rank test: χ² = 0.20; <i>P</i> = 0.651.</p