Higher serum total bilirubin concentration is associated with lower risk of renal insufficiency in an adult population.

BACKGROUND: Chronic inflammation is proposed to play a central role in the pathogenesis of chronic kidney disease (CKD), and serum bilirubin has antioxidant and anti-inflammatory effects. We investigated the association between serum total bilirubin (Tb) concentration and renal function in an adult population. METHODS: We conducted a cross-sectional study and collected anthropometric measurements, fasting blood tests, lifestyle habits and medical history of 3876 subjects attending a health examination. Renal insufficiency was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m(2) calculated by using the CKD-EPI equation. RESULTS: Serum Tb concentrations were higher in subjects without renal insufficiency than in those with renal insufficiency. Multivariable linear regression analysis showed that Tb concentration was positively associated with eGFR after adjusting for important CKD risk factors (P=0.04). Multivariable logistic regression analysis also revealed that higher Tb concentration (each increment of 1.71 µmol/L) (0.1 mg/dL) was associated with a reduced risk of renal insufficiency: odds ratios were 0.94 (P=0.005) for men and 0.90 (P=0.015) for women, respectively. When subjects were divided into quartiles of serum Tb, multivariable-adjusted odds ratios for renal insufficiency comparing the fourth to the first Tb quartile were 0.49 (P=0.001) for men and 0.35 (P=0.003) for women. A stepwise exclusion of subjects, first those with possible liver disease and second, those with CKD stage 4 and 5, showed consistent results. CONCLUSION: Higher serum Tb concentration was associated with lower risk of renal insufficiency, regardless of other conventional CKD risk factors.

Serum total bilirubin concentrations are inversely associated with total white blood cell counts in an adult population.

BACKGROUND: Several studies have shown that serum bilirubin has a protective effect against cardiovascular disease and that inflammation plays an important role in its pathogenesis. This cross-sectional study investigated whether there was an association between blood total white blood cell count, a simple indicator of inflammation, and serum total bilirubin concentration in a cohort of an adult population in Taiwan. METHODS: A total of 2458 apparently healthy adults (1246 men and 1212 women) who attended health examination at a medical centre in central Taiwan were enrolled. We collected anthropometric measurements, fasting blood test results, lifestyle habits and medical history. RESULTS: Total white blood cell counts decreased progressively when the concentrations of total bilirubin increased as demonstrated in the total bilirubin quartiles. Both total bilirubin concentrations and total white blood cell counts showed significant correlations with the components of metabolic syndrome, including triglyceride and high-density lipoprotein cholesterol concentrations. Multivariate linear regression analysis revealed that, for both genders, total bilirubin showed an independent negative correlation with total white blood cell count after adjusting for conventional cardiovascular risk factors. CONCLUSIONS: Higher serum total bilirubin concentrations within the reference range were associated with lower blood total white blood cell counts, regardless of other classical cardiovascular risk factors.

Changes in preterm breast milk nutrient content in the first month.

BACKGROUND: The primary aim of the study was to investigate the changes in composition of breast milk from mothers with preterm infants (gestation age < 35 weeks) during the first 4-6 weeks of lactation. METHODS: Breast milk from 17 mothers who had delivered preterm infants was collected longitudinally for 4-6 weeks. Breast milk from 15 mothers of full-term infants was also collected at the 1(st) week and 4(th) week. Fat, protein, lactose, energy, minerals (calcium and phosphate), and immune components [secretory immunoglobulin A (IgA), leptin, lysozyme, and lactoferrin] content were measured weekly in each participant. A mid-infrared human milk analyzer was used to measure the protein, fat, and lactose contents. Calcium and phosphate components were checked via spectrophotometry. The concentrations of major immune components (secretory IgA, lactoferrin, lysozyme, and leptin) were quantified using enzyme-linked immunosorbent assay kits. RESULTS: Eighty samples from 17 preterm mothers were collected. The mean gestational age was 29.88 ± 2.39 weeks. There were significant changes in nutrient components during these periods, with increases in lactose (p < 0.001), lipid (p = 0.001), calorie (p = 0.012), and phosphate (p = 0.022) concentration and decreases in protein (p < 0.001) and secretory IgA (p < 0.001) concentration. There were no differences in calcium (p = 0.919), lactoferrin (p = 0.841), leptin (p = 0.092), and lysozyme (p = 0.561) levels. Furthermore, there were no significant differences in most components of breast milk between full-term and preterm mothers. CONCLUSION: The longitudinal study revealed significant changes in macronutrient contents and secretory IgA concentration in preterm milk over the 4-6 week period, which is compatible with the results of previous studies. The quantification of phosphate in preterm breast milk was lower than the normal range, suggesting that close monitoring of body bone mass may be indicated. More studies are warranted to evaluate the clinical significance of alterations of major milk components during the postnatal stage.