Incidence and risk factors of coronary heart disease in elderly patients on chronic hemodialysis

Does Omega-3 supplementation decrease carotid intima-media thickening in hemodialysis patients?

Objective:

A randomized, double-blind, placebo-controlled clinical trial was performed to assess the effect of omega-3 supplementation (3 g/day) on atherosclerosis progression by measuring carotid intima-media thickness (cIMT) in hemodialysis (HD) patients.

Methods:

A total of 54 HD patients were randomized into two groups: Intervention group (n = 27), in which patients were given 3 g/day omega-3 for 6 months and placebo group (n = 27), in which patients received placebo using the same administration protocol. All patients underwent a carotid artery ultrasound scan to measure cIMT at baseline and at 6 months.

Findings:

cIMT decreased significantly in omega-3 group (0.79 ± 0.21 mm at baseline vs. 0.65 ± 0.18 mm at 6 months, P < 0.001). On the other hand, a nonsignificant increase in cIMT was seen in placebo group (0.75 ± 0.17 mm at baseline vs. 0.79 ± 0.17 mm at 6 months, P = 0.12). Moreover, cIMT was statistically significantly different between omega-3 and placebo groups at 6 months (P < 0.001). After 6 months, a statistically significant increase was observed in high-density lipoprotein level in omega-3 group compared to placebo group (P = 0.03). Urea reduction ratio was also statistically significantly higher in omega-3 than placebo group at 6 months (P = 0.03). No significant difference was observed in terms of other variables between the two groups.

Conclusion:

These data suggested that omega-3 supplementation plays a protective role in the progression of atherosclerosis in HD patients.

Vitamin D status and associated metabolic risk factors among North Korean refugees in South Korea: a cross-sectional study

OBJECTIVE

Vitamin D deficiency is now recognised as a common health problem associated with various chronic diseases; however, it has not been fully elucidated among the minority groups. Here, we aimed to investigate the prevalence of vitamin D deficiency and its associated metabolic risk factors among North Korean refugees living in South Korea.

DESIGN

Cross-sectional analysis from the longitudinal cohort, the North Korean refugee health in South Korea (NORNS) study.

PARTICIPANTS

A total of 386 North Korean refugees aged ≥30 years, who measured serum 25-hydroxy vitamin D (25(OH)D) level.

RESULTS

The prevalence of vitamin D deficiency (25(OH)D <20 ng/mL) was 87% and no participants had an adequate vitamin D level (25(OH)D ≥30 ng/mL). Underweight participants (body mass index (BMI) <18 kg/m(2)) had significantly lower 25(OH)D levels than individuals with normal BMI (≥18.5 and<23 kg/m(2)). In the multivariate logistic regression analysis, the lowest 25(OH)D level (<10 ng/mL) was significantly associated with metabolic syndrome (OR, 6.37, 95% CI 1.34 to 30.3), high triglyceride (OR, 6.71, 95% CI 1.75 to 25.7), and low high-density lipoprotein (OR, 5.98, 95% CI 1.54 to 23.2) compared with 25(OH)D levels ≥20 ng/mL after adjusting for age, sex, season, length of residence in South Korea, physical activity and BMI.

CONCLUSIONS

Vitamin D deficiency is very common among North Korean refugees in South Korea. Despite their lower BMI, vitamin D deficiency was associated with metabolic syndrome in this population.

Treatment of 25-OH vitamin D deficiency in older men with chronic kidney disease stages 3 and 4 is associated with reduction in cardiovascular events

Observational studies in healthy people suggest an inverse relationship between serum 25-hydroxyvitamin D (25OHD) levels and cardiovascular (CV) mortality. Treating vitamin D deficiency in patients with moderate chronic kidney disease (CKD) may reduce CV events in this high-risk population. Study data were abstracted from Harry S. Truman Memorial Veterans Hospital electronic medical record system. The medical records of all veterans who had CKD stages 3 and 4 and had 25OHD levels determined from April 2006 to September 2007 were reviewed. Patients with 25OHD deficiency, serum level <30 ng/mL, were included (N = 126, all men, mean age = 70 years). Successful 25OHD replacement was defined as prescription of ergocalciferol sufficient to increase serum 25OHD level by 25% from baseline within 6 months (treatment group, n = 90). Otherwise patients were considered as untreated controls (n = 36). The date when the 25OHD level was drawn was considered as the date of inclusion. All the patients were followed up from the date of inclusion until July 2009 to capture CV events prospectively. During mean follow-up of 27.2 months, 44% of the controls had CV events, whereas only 21% of the patients in the treatment group had CV events (P = 0.001). In multivariate logistic regression analysis, adjusting for CV disease predictors age, initial parathyroid hormone level, statin use, history of CV disease, and glomerular filtration rate, the estimated odds ratio for 25OHD replacement status was 0.37 (95% confidence interval: 0.14-1.0). Treatment of 25OHD deficiency with ergocalciferol in patients with moderate CKD is associated with significant reduction in CV events.

Vitamin D deficiency and cardiovascular disease: potential mechanisms and novel perspectives

Interest in contemporary vitamin D research has been sparked in recent years, stemming from the identification of vitamin D receptors in virtually all cells as well as the enzymatic machinery necessary to produce its active form. Both epidemiological and in-vitro studies have linked vitamin D deficiency to enigmatic diseases including cardiovascular disease; however, a clear mechanistic link remains missing. This review highlights conclusions of observational studies, in-vitro experiments and randomized-controlled trials that aimed to link deficiency of the sunshine vitamin to one of the leading causes of death in the world, cardiovascular disease. Furthermore, putative mechanisms viewed from a novel perspective are also discussed.

Serum levels of fibroblast growth factor 19 are inversely associated with coronary artery disease in chinese individuals

Background

The fibroblast growth factor 19 (FGF19) has been implicated in recent studies as a potential regulator of glucose and lipid metabolism, which may lead to atherosclerosis. Here, we investigated the association of FGF19 with the presence and severity of coronary artery disease (CAD) in a Chinese population.

Methods

A total of 315 patients with suspected or established CAD, including 205 males and 110 postmenopausal females, were enrolled and assessed by coronary angiography. CAD severity was determined by the Gensini score. Serum FGF19 was measured by quantitative sandwich ELISA.

Results

FGF19 levels were not significantly different between male and female patients (median [interquartile range], 143.40 [87.96–250.80] vs. 141.60 [87.13–226.32] pg/mL, P = 0.773). CAD patients had lower levels of FGF19 than those without CAD (128.20 [80.62–226.58] vs. 188.00 [105.10–284.70] pg/mL, P = 0.007). FGF19 was negatively correlated with 2hPG (r = –0.150, P = 0.008), FINS (r = –0.169, P = 0.004), HOMA-IR (r = –0.171, P = 0.004), and the Gensini score (r = –0.141, P = 0.012), but positively correlated with HDL-c (r = 0.116, P = 0.041) and adiponectin (r = 0.128, P = 0.024). Moreover, FGF19 was found to be independently correlated with 2hPG (β = –0.146, P = 0.022) and adiponectin (β = 0.154, P = 0.016). After adjusting for other CAD risk factors, FGF19 was demonstrated to be an independent factor for Gensini score (β = –0.140, P = 0.019) and the presence of CAD (β = –1.248, P = 0.036).

Conclusions

Serum FGF19 is associated with the presence and severity of CAD in a Chinese population.

Vitamin D and cardiovascular disease will it live up to its hype?

Substantial evidence suggests that a large portion of the population have suboptimal levels of vitamin D, which may adversely affect the cardiovascular (CV) system, including increasing levels of parathyroid hormone, activating the renin-angiotensin-aldosterone system, and increasing insulin resistance, thus leading to hypertension and left ventricular hypertrophy, metabolic syndrome/diabetes mellitus, systemic inflammation, and increased risk of atherosclerosis and CV disease events. We review the evidence that vitamin D deficiency is associated with incident CV disease events, as well as evidence that vitamin D supplementation is associated with reduction in CV diseases. Although the current evidence has created substantial hype, randomized controlled trials are needed to determine whether routine vitamin D assessment and supplementation will improve CV outcomes.

[Vitamin D and hypertension]

Low levels of vitamin D, defined as levels of 25-hydroxyvitamin D < 20-30 ng/ml, is a prevalent problem in the general population. Besides the classic relation with musculoskeletal disease, vitamin D has been also related to autoimmune diseases, cancer, metabolic diseases or cardiovascular diseases. High blood pressure, as the main cardiovascular risk factor, also has been related to vitamin D deficiency, constituting two prevalent worldwide health problems. Therefore, this article reviews the most important studies that combine both pathologies, the biological mechanism that relate them and the current evidence about the effect of vitamin D supplementation on hypertension.

FGF-23 and PTH levels in patients with acute kidney injury: A cross-sectional case series study

Background

Fibroblast growth factor-23 (FGF-23), a novel regulator of mineral metabolism, is markedly elevated in chronic kidney disease and has been associated with poor long-term outcomes. However, whether FGF-23 has an analogous role in acute kidney injury is unknown. The goal of this study was to measure FGF-23 levels in critically ill patients with acute kidney injury to determine whether FGF-23 levels were elevated, as in chronic kidney disease.

Methods

Plasma FGF-23 and intact parathyroid hormone (PTH) levels were measured in 12 patients with acute kidney injury and 8 control subjects.

Results

FGF-23 levels were significantly higher in acute kidney injury cases than in critically ill subjects without acute kidney injury, with a median FGF-23 level of 1948 RU/mL (interquartile range (IQR), 437-4369) in cases compared with 252 RU/mL (IQR, 65-533) in controls (p = 0.01). No correlations were observed between FGF-23 and severity of acute kidney injury (defined by the Acute Kidney Injury Network criteria); among patients with acute kidney injury, FGF-23 levels were higher in nonsurvivors than survivors (median levels of 4446 RU/mL (IQR, 3455-5443) versus 544 RU/mL (IQR, 390-1948; p = 0.02). Severe hyperparathyroidism (defined as intact PTH >250 mg/dL) was present in 3 of 12 (25%) of the acute kidney injury subjects versus none of the subjects without acute kidney injury, although this result did not meet statistical significance.

Conclusions

We provide novel data that demonstrate that FGF-23 levels are elevated in acute kidney injury, suggesting that FGF-23 dysregulation occurs in acute kidney injury as well as chronic kidney disease. Further studies are needed to define the short- and long-term clinical effects of dysregulated mineral metabolism in acute kidney injury patients.

Hospital admissions in elderly patients on chronic hemodialysis

BACKGROUND

The purpose of this study was to determine whether number of hospital admissions per patient per year (n/[pt-yr]) and hospital days per patient per year (d/[pt-yr]) differ between elderly and younger patients on chronic hemodialysis (HD).

PATIENTS AND METHODS

In a retrospective cohort analysis of incident HD patients in one dialysis unit over 15 years, we compared 166 HD patients older than 70 years (77.1 ± 4.7 yrs) at the onset of HD (group A) and 216 patients younger than 70 years both at onset (57.1 ± 7.6 yrs) and at the end of the HD period (group B). Eighty (48.2%) of group A and 141 (65.3%) patients of group B had diabetes mellitus.

RESULTS

No differences were noted in the overall hospitalization rate, presented as mean, {95% Confidence interval} (group A 2.40 {2.04-2.75}, group B 2.03 {1.89-2.16} n[pt-yr]) and days/[pt-year] (group A 33.6 {25.3-41.8}, group B 24.1 {18.9-29.23}). Group A had higher number of hospitalization days (P = 0.012) for surgery or trauma and higher rate (P = 0.045) and days (P = 0.041) of hospitalization for miscellaneous causes, primarily pulmonary disease, or malignancy. Among diabetic patients, group A had only a greater number of hospital days for cardiac disease (P = 0.050). Among patients without diabetes, group A had a higher number for hospital days for surgery or trauma (P = 0.027). All other univariate comparisons were not significant. Multiple linear regression identified comorbidity, quantified by the Charlson index, Caucasian race and poor compliance with the HD schedule as predictors of admission rate and days per year for vascular access issues and comorbidity, poor compliance, and advanced age at onset of HD as predictors of admission for causes other than vascular access related.

CONCLUSION

Hospitalizations, which affect quality of life, differ little between elderly and younger patients on HD. Therefore, hospitalizations do not constitute an argument for restricting access to HD to elderly patients.

Vitamin D deficiency an important, common, and easily treatable cardiovascular risk factor?

Vitamin D deficiency is a highly prevalent condition, present in approximately 30% to 50% of the general population. A growing body of data suggests that low 25-hydroxyvitamin D levels may adversely affect cardiovascular health. Vitamin D deficiency activates the renin-angiotensin-aldosterone system and can predispose to hypertension and left ventricular hypertrophy. Additionally, vitamin D deficiency causes an increase in parathyroid hormone, which increases insulin resistance and is associated with diabetes, hypertension, inflammation, and increased cardiovascular risk. Epidemiologic studies have associated low 25-hydroxyvitamin D levels with coronary risk factors and adverse cardiovascular outcomes. Vitamin D supplementation is simple, safe, and inexpensive. Large randomized controlled trials are needed to firmly establish the relevance of vitamin D status to cardiovascular health. In the meanwhile, monitoring serum 25-hydroxyvitamin D levels and correction of vitamin D deficiency is indicated for optimization of musculoskeletal and general health.

Magnesium supplementation helps to improve carotid intima media thickness in patients on hemodialysis

BACKGROUND

The atherosclerotic process progresses more dynamically in hemodialysis (HD) patients than in the general population. In HD patients, lower magnesium levels were reported to be associated with increased atherosclerosis of the common carotid artery. We tested the hypotheses that magnesium supplementation helps to improve carotid intima media thickness (IMT) in HD patients.

MATERIALS AND METHODS

A total of 47 patients on HD were included in the study. Patients were randomly divided into two groups: group A (Mg group), in which patients were given magnesium citrate orally at a dosage of 610 mg every other day for 2 months and group B (control group), in which patients received only calcium acetate therapy as a phosphate binder. At baseline and 2 months later, all patients underwent a carotid artery ultrasound scan to measure carotid IMT.

RESULTS

At the end of 2 months, mean serum calcium, phosphorus, and calcium x phosphorus product were not changed in both groups. As expected, mean serum Mg level significantly increased in the Mg group at the end of 2 months. In addition, serum parathyroid hormone (PTH) level significantly decreased in the Mg group at the end of 2 months (P = 0.003). Baseline carotid IMT was similar between the groups. Bilateral carotid IMT was significantly improved in patients treated with magnesium citrate compared to initial values (P = 0.001 for left, P = 0.002 for right).

CONCLUSION

Based on the present data, magnesium may play an important protective role in the progression of atherosclerosis in patients on dialysis. Further studies are needed to assess more accurately the role of magnesium in atherosclerotic regression in dialysis patients.