Association between obesity and risk of chronic kidney disease: A nationwide Cohort study in Taiwan

Elevated Crude Mortality in Obese Chronic Kidney Disease Patients with Loss of Exercise Habit: A Cohort Study of the Japanese General Population

Objective The relationship between obesity and risk of death in chronic kidney disease (CKD) patients remains controversial. In addition, no clear evidence has been accumulated regarding whether or not exercise improves mortality in CKD patients. Methods The original cohort was based on a Japanese general population of 685,889 people from 40 to 74 years old who had undergone annual specific health checkups. The number of all-cause deaths during follow-up (mean, 4.7 years) in this study was 1,490. Information on walking and exercise habits was obtained by questionnaires. The study population was divided into 4 categories by the combination of CKD and obesity [body mass index (BMI) ≥25.0 kg/m2]. Changes in the BMI and walking and exercise habits were determined by results for the first year and following year. Results Obese CKD patients with weight gain (BMI increase by more than +1.0 kg/m2/year) showed a higher crude mortality (1.32%) than those with a stable BMI (within ±1.0 kg/m2/year; 0.69%). In the obese CKD population, mortality was higher with loss of exercise habits (0.96%) than in those continuously maintaining exercise habits (0.52%). The age- and sex-adjusted hazard ratio for all-cause death was 2.23 in the group with weight gain compared to the group with stable weight (p<0.01) and 2.08 in the group with loss of exercise habits compared to those who maintained exercise habits (p<0.01). Conclusion This observational cohort study suggested that loss of exercise habits as well as weight gain of more than 1 kg/m2/year might worsen all-cause mortality in the obese CKD population.

Body weight fluctuation is associated with rapid kidney function decline

OBJECTIVE

This study aimed to evaluate the effects of body weight fluctuations on kidney function deterioration in a prospective cohort of individuals with normal kidney function.

METHODS

Data were obtained from the Korean Genome and Epidemiology Study. Body weight fluctuations were determined using average successive variability (ASV), which was defined as the average absolute body weight change using repeated measurements for all participants. The decline of the estimated glomerular filtration rate (eGFR) over time was calculated using linear regression analysis of serial eGFR measurements for each patient. Rapid eGFR decline was defined as an average eGFR decline > 3 mL/min/1.73 m² per year.

RESULTS

A total of 6,790 participants were analyzed. During a median follow-up of 11.7 years, rapid eGFR decline was observed in 913 (13.4%) participants. When the participants were categorized into tertiles according to ASV, rapid eGFR decline was more prevalent in the highest ASV tertile group than in the lowest. Analyses using multiple logistic regression models revealed that the risk of rapid eGFR decline was increased in the highest ASV tertile group compared with the lowest (odds ratio: 1.66).

CONCLUSIONS

Body weight fluctuations were significantly associated with an increased risk of rapid kidney function decline in participants with normal kidney function.

Association between Body Mass Index and Chronic Kidney Disease in Asian Populations: A Participant-level Meta-Analysis

Obesity and chronic kidney disease (CKD) are major public health problems worldwide. However, the association between body mass index (BMI) and CKD is inconclusive in Asians. In this meta-analysis, eight population-based studies, from China, India, Russia (Asian), Singapore and South Korea, provided individual-level data (n=50037). CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m². BMI was analyzed both as a continuous variable and in three categories: <25kg/m², normal; 25-29.9kg/m², overweight; and ≥30kg/m², obese. The association between BMI and CKD was evaluated in each study using multivariable logistic regression models and individual estimates were pooled using random-effect meta-analysis to obtain the pooled odds ratio (OR) and 95% confidence interval (CI). Associations were also evaluated in subgroups of age, gender, smoking, diabetes, and hypertension status. Of 50037 adults, 4258 (8.5%) had CKD. 13328 (26.6%) individuals were overweight while 4440 (8.9%) were obese. The prevalence of any CKD ranged from 3.5% to 29.1% across studies. In pooled analysis, both overweight and obesity were associated with increased odds of CKD, with pooled OR (95% CI) of 1.15 (1.03-1.29) and 1.23 (1.06-1.42), respectively. In subgroup analyses, significant associations between BMI and CKD were observed in adult males, non-smokers, and those with diabetes and arterial hypertension (all p<0.05). When evaluated as a continuous variable, BMI was not significantly associated with CKD. If confirmed in longitudinal studies, these results may have clinical implications in risk stratification and preventive measures, given that obesity and CKD are two major chronic diseases with substantial public health burden worldwide.

Secular decreasing trends in gastric cancer incidence in Taiwan: A population-based cancer registry study

BACKGROUND

Gastric cancer remains a leading cause of cancer death worldwide. In Taiwan, gastric cancer is the sixth leading cause of cancer mortality in both males and females.

AIM

To evaluate secular trends in gastric cancer incidence according to age, sex, and Helicobacter pylori (H. pylori) treatment in Taiwan.

METHODS

In this population-based study, we used the national Taiwan Cancer Registry database. Annual percent changes in incidence rates were used to describe secular trends in incidence rates and sex ratios of gastric cancer in Taiwan. Pearson’s product-moment correlation coefficients were used to analyze the correlation between annual age-adjusted incidence rates and the annual number of patients treated with antibiotic therapy for H. pylori infection.

RESULTS

The annual percent changes showed continuously decreasing rates of gastric cancer among both males and females. However, the decreasing trends differed by sex, with an annual percent change of -2.58% in males and -2.14% in females. The age-specific incidence rates increased with age. Within the same age group, more recent time periods showed lower incidence rates than greater time periods. Similarly, the sex ratio was lower in later birth cohorts than in earlier birth cohorts. Age-adjusted incidence rates substantially decreased with increasing numbers of patients being treated with antibiotic therapy for H. pylori infection during 2005 to 2016 (r = 0.72).

CONCLUSION

We observed steadily decreasing trends with differential sex ratios in the incidence of gastric cancer in Taiwan. These results support H. pylori eradication programs in Taiwan.

Obesity measures at baseline, their trajectories over time, and the incidence of chronic kidney disease: A 14 year cohort study among Korean adults

BACKGROUND AND AIMS

We investigated the association of baseline obesity measures, i.e. body mass index (BMI), waist circumference (WC), hip circumference (HC), and waist-hip ratio (WHR), and their trajectories over time with incident chronic kidney disease (CKD).

METHODS AND RESULTS

Utilizing data from 2001 to 2014 for 9796 Korean adults without CKD at baseline, the association of baseline obesity measures with incident CKD was evaluated using logistic regression. Further, among 5605 subjects with repeated measures, the effect of the trajectories in obesity measures on CKD incidence was investigated via Cox regression. Baseline obesity in terms of BMI, WC, and HC increased the odds of incident CKD (odds ratio (OR) 1.19, 95% confidence interval (CI) 1.05-1.33; OR 1.22, 95% CI 1.07-1.38; and OR 1.25, 95% CI 1.11-1.41, respectively), while baseline WHR did not show such an association. A "became non-obese" BMI, WC, or WHR trajectory, and a "constantly not large" HC trajectory decreased the hazard of incident CKD (hazard ratio (HR) 0.70, 95% CI 0.50-0.99; HR 0.61, 95% CI 0.40-0.92; HR 0.55, 95% CI 0.35-0.85; and HR 0.81, 95% CI 0.69-0.95, respectively) when compared with a "constantly obese or became obese" trajectory.

CONCLUSION

Both baseline obesity and obesity trajectories over time were associated with CKD incidence. BMI and WC were equally good measures of CKD risk, while WHR was not. Separately examining WC and HC components of WHR (= WC/HC) may explain WHR's inconsistency, and WHR's usefulness as a measure of CKD risk should be reevaluated.

Association between weight status, metabolic syndrome, and chronic kidney disease among middle-aged and elderly Chinese

BACKGROUND AND AIMS

Obesity often initiates or coexists with certain metabolic abnormalities. This study sought to examine the independent and joint relations of weight and metabolic syndrome (MetS) with incident chronic kidney disease (CKD) among Chinese elderly people.

METHODS AND RESULTS

A total of 15,229 participants (mean age: 62.8 years) from the Dongfeng-Tongji cohort with complete baseline questionnaire and medical examination data were followed from 2008 to 2010 to 2013. All participants were categorized into four phenotypes: metabolically healthy non-overweight/obesity (MHNO), metabolically healthy overweight/obesity (MHO), metabolically unhealthy non-overweight/obesity (MUNO), metabolically unhealthy overweight/obesity (MUO). Multivariable-adjusted logistic regression models were applied to estimate the odds ratios (ORs) and confidence intervals (CIs) of four phenotypes with the risk of incident CKD, which was defined as estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73 m². A total of 1151 CKD cases were identified during a mean of 4.6-year follow-up. After adjusting for potential confounders, both overweight/obesity and MetS were associated with higher risk of CKD, and the ORs (95% CI) were 1.32 (1.15-1.52) and 1.50 (1.31-1.73), respectively. The risk of CKD was progressively higher in MHO (1.31, 1.09-1.57), MUNO (1.54, 1.22-1.93), and MUO (2.05, 1.73-2.42) as compared with MHNO phenotype, without significant multiplicative interaction between overweight/obesity and MetS (P_interaction = 0.906). These associations were slightly stronger among those aged >60 years or with baseline diabetes.

CONCLUSION

Both overweight/obesity and MetS were associated with an increased risk of CKD. It is worth noting that MHO and MUNO also have an elevated risk. Maintaining both normal weight and healthy metabolic profile is recommended.

Bariatric Surgery Improves Renal Function: a Large Inner-City Population Outcome Study

BACKGROUND

Bariatric surgery is associated with improved renal dysfunction in general population studies. The study examined the effects of bariatric surgery on renal function in a predominantly Hispanic and African American population at a community hospital in New York, USA.

METHODS

This retrospective study analyzed prospectively collected bariatric surgical data from 2247 patients (89% female) who underwent bariatric surgery at a single center. Changes in glomerular filtration rate (eGFR), urine albumin-creatinine ratio (UACR), micro- and macroalbuminuria, and hyperfiltration, which were measured preoperatively and then yearly for 3 years postoperatively, were evaluated with t tests and logistic regression analysis, after adjusting for confounding variables. The mean age of the patients at surgery was 37.1 years; the mean preoperative body mass index was 45 ± 7 kg/m².

RESULTS

The results obtained 3 years postoperatively showed the following significant improvements compared with the preoperative values: mean UACR decreased from 40.3 to 11.1 mg/g, mean eGFR improved from 79.4 to 87.3 mL/min, the prevalence of microalbuminuria decreased from 13.7 to 6.2%, the prevalence of macroalbuminuria decreased from 2.5 to 0%, and the prevalence of hyperfiltration decreased from 4.4 to 2.7% (all P < .0001). In adjusted multivariate regression analysis, these results remained significant after adjusting for age, sex, race, type of surgery, and presence of diabetes mellitus or hypertension.

CONCLUSION

In this large study at an inner-city hospital, bariatric surgery was associated with significant improvements in renal dysfunction parameters. These results could assist with informed decisions regarding indications for bariatric surgery.

Self-reported snoring is associated with chronic kidney disease independent of metabolic syndrome in middle-aged and elderly Chinese

AIMS/INTRODUCTION

To investigate the correlation between snoring and chronic kidney disease (CKD), and explore whether metabolic syndrome (MetS) plays an important role in this relationship among middle-aged and elderly Chinese.

MATERIALS AND METHODS

The participants included in the present study were categorized into three subgroups based on self-reported snoring frequency (regularly [≥3 times per week], occasionally [between 'regularly' and 'never'] or never [<1 time per month]). An estimated glomerular filtration rate <60 mL/min/1.73 m2 was considered as CKD. We diagnosed MetS based on the 2004 Chinese Diabetes Society criteria. We explored the relationship between snoring and CKD by using multiple logistic regressions.

RESULTS

The frequency of MetS, MetS components and CKD was dramatically higher in regular snorers than in non-snorers and occasional snorers. The odds ratios for MetS and all the MetS elements, except for hyperglycemia, increased progressively with the snoring frequency (P < 0.001). Upon additional adjustment for other MetS components, snoring was not significantly related with hypertension; however, the associations between snoring frequency and overweight/obesity and dyslipidemia became attenuated, but still remained statistically significant (P < 0.01). Interestingly, odds ratios for CKD also increasingly augmented with snoring frequency (P < 0.001). Upon further adjustment for individual MetS components or MetS, regular snoring also resulted in a significantly increased odds ratio for CKD (odds ratio 1.72; P = 0.034) relative to non-snoring.

CONCLUSIONS

Self-reported snoring is closely associated with CKD independent of MetS among middle-aged and elderly Chinese.

Changes of Percent Body Fat as a Useful Surrogate for Risk of Declined Renal Function

The association between anthropometric indices with chronic kidney disease (CKD) was examined previously. However, the effect of body fat on renal function was not determined clearly. Our aim was to investigate the association of percent body fat (PBF) and renal function in adult population from health examination in Tri-Service General Hospital (2010–2016). 35087 participants aged 20 years and older were enrolled in the study. PBF was measured by bioelectrical impedance analysis (BIA). Estimation of renal function was performed by Taiwanese MDRD equation. Optimal cut-off values of PBF was accessed by a receiver–operator characteristic (ROC) curve analysis. Multivariate regression models were used in the relationship among changes of PBF, renal function, and future CKD. In terms of baseline PBF for CKD, optimal cut-off values of PBF in males and females were 21.55 and 40.75. The changes of PBF were more closely associated with renal function decline than waist circumference (WC) with β values of −0.173 (95% CI: −0.233, −0.112) and −0.077 (95% CI: −0.104, −0.049), respectively. After stratified by gender, this relationship remained significant in male population with β values of −0.276 (95% CI: −0.371, −0.181) and −0.159 (95% CI: −0.207, −0.112), respectively. Female subjects with increased baseline PBF over cut-off values had increased risk for predicting the future CKD with odd ratios (ORs) of 2.298 (95% CI: 1.006–5.252). Body fat had detrimental impact on renal function and development of CKD in adult population. Measurement of PBF for surveillance of renal function impairment was warranted.

Elevated serum levels of procollagen C-proteinase enhancer-1 in patients with chronic kidney disease is associated with a declining glomerular filtration rate

BACKGROUND

Procollagen C-proteinase enhancer-1 (PCPE-1) is a 55 kDa glycoprotein, which increases the activity of procollagen C-proteinases that break down C-terminal propeptides. Studies have shown that PCPE-1 is involved in the fibrotic process that occurs in various tissues and organs. Our review of the literature revealed no data concerning the relation between PCPE-1 and chronic kidney disease (CKD). The purpose of this study was to determine PCPE-1 levels in CKD.

METHODS

One hundred thirty-one CKD patients and 34 healthy controls were included in our study. Demographic data were recorded, and routine biochemical tests were performed. Blood specimens were collected for PCPE-1 investigation. Demographic data, biochemical test results and PCPE-1 levels were compared between the control and patient groups. Parameters affecting PCPE-1 levels in our patient group were assessed.

RESULTS

Procollagen C-proteinase enhancer-1 levels were significantly higher in our patient group compared to the control group. Parameters affecting PCPE-1 elevation in the patient group were identified as systolic blood pressure, blood urea nitrogen, phosphorus, haemoglobin, intact parathormone levels, glomerular filtration rate and body mass index.

CONCLUSION

We determined high PCPE-1 levels in CKD patients. PCPE-1 levels being negatively correlated with glomerular filtration rate suggests that PCPE-1 may be associated with progression in CKD patients.

Probiotic Lactobacillus paracasei HII01 protects rats against obese-insulin resistance-induced kidney injury and impaired renal organic anion transporter 3 function

The relationship between gut dysbiosis and obesity is currently acknowledged to be a health topic which causes low-grade systemic inflammation and insulin resistance and may damage the kidney. Organic anion transporter 3 (Oat3) has been shown as a transporter responsible for renal handling of gut microbiota products which are involved in the progression of metabolic disorder. The present study investigated the effect of probiotic supplementation on kidney function, renal Oat3 function, inflammation, endoplasmic reticulum (ER) stress, and apoptosis in obese, insulin-resistant rats. After 12 weeks of being provided with either a normal or a high-fat diet (HF), rats were divided into normal diet (ND); ND treated with probiotics (NDL); HF; and HF treated with probiotic (HFL). Lactobacillus paracasei HII01 1 × 108 colony forming unit (CFU)/ml was administered to the rats daily by oral gavage for 12 weeks. Obese rats showed significant increases in serum lipopolysaccharide (LPS), plasma lipid profiles, and insulin resistance. Renal Oat 3 function was decreased along with kidney dysfunction in HF-fed rats. Obese rats also demonstrated the increases in inflammation, ER stress, apoptosis, and gluconeogenesis in the kidneys. These alterations were improved by Lactobacillus paracasei HII01 treatment. In conclusion, probiotic supplementation alleviated kidney inflammation, ER stress, and apoptosis, leading to improved kidney function and renal Oat3 function in obese rats. These benefits involve the attenuation of hyperlipidemia, systemic inflammation, and insulin resistance. The present study also suggested the idea of remote sensing and signaling system between gut and kidney by which probiotic might facilitate renal handling of gut microbiota products through the improvement of Oat3 function.