Effects of Weight Loss Speed on Kidney Function Differ Depending on Body Mass Index in Nondiabetic Healthy People: A Prospective Cohort

Obesity, Weight Loss, Lifestyle Interventions, and Autosomal Dominant Polycystic Kidney Disease

Obesity remains a growing public health concern in industrialized countries around the world. The prevalence of obesity has also continued to rise in those with chronic kidney disease. Epidemiological data suggests those with overweight and obesity, measured by body mass index, have an increased risk for rapid kidney disease progression. Autosomal dominant polycystic kidney disease causes growth and proliferation of kidney cysts resulting in a reduction in kidney function in the majority of adults. An accumulation of adipose tissue may further exacerbate the metabolic defects that have been associated with ADPKD by affecting various cell signaling pathways. Lifestyle interventions inducing weight loss might help delay disease progression by reducing adipose tissue and systematic inflammation. Further research is needed to determine the mechanistic influence of adipose tissue on disease progression.

The risk of consequent nephropathy following initial weight loss in diabetic patients treated with sodium glucose cotransporter 2 inhibitors

BACKGROUND

There is a controversy over the association between obesity and the risk of renal events in patients with type 2 diabetes mellitus (T2DM). Furthermore, whether body weight (BW) loss following sodium glucose cotransporter 2 inhibitor (SGLT2i) treatment associated with risk of adverse renal events is unknown.

METHODS

We used medical data from a multi-center healthcare provider in Taiwan, enrolling 8992 T2DM patients with a baseline/following-up BW data available after around 12 weeks of SGLT2i treatment, from June 1, 2016 to December 31, 2018. Patients were followed up until the occurrence of composite renal outcome (estimated glomerular filtration rate decline > 40% or end-stage kidney disease) or the end of study period, whichever occurred first.

RESULTS

Participants were divided into six baseline BMI categories: < 18.5 (n = 55); 18.5-22.9 (n = 985); 23.0-24.9 (n = 1389); 25.0-29.9 (n = 3941); 30.0-34.9 (n = 1973); and ≥ 35.0 kg/m² (n = 649). There were 38.9%, 23.5%, 24.7%, 8.4%, 2.7%, and 1.8% of patients experienced no-BW loss, initial BW loss of 0.0-2.4%, 2.5-4.9%, 5.0-7.4%, 7.5-9.9%, and ≥ 10.0%, associated with SGLT2i treatment, respectively. Compared with patients with normal BMI (BMI: 18.5-22.9 kg/m²), underweight (BMI: < 18.5 kg/m²) was associated with a higher risk of composite renal outcome (adjusted hazard ratio (aHR) [95% confidence intervals (CI)]: 2.17; [1.16-4.04]), whereas pre-obese (BMI: 25.0-29.9 kg/m²) associated with the lowest risk of composite renal outcome (0.52; [0.40-0.68]) after multivariate adjustment. Compared with those without BW loss after SGLT2i treatment, BW loss of 0.0-2.4% (0.55; [0.43-0.70]) and 2.5-4.9% (0.78; [0.63-0.98]) were associated with a lower risk, whereas BW loss ≥ 10.0% associated with a higher risk of composite renal outcome (1.61; [1.06-2.46]) after multivariate adjustment.

CONCLUSION

A modest BW loss of 0-5% associated with SGLT2i treatment was associated with a favorable renal outcome. Caution should be taken for whom are underweight at baseline or have a pronounced BW loss ≥ 10.0% associated with SGLT2i treatment, which was associated with a worse renal outcome.

Rapid Weight Change Over Time Is a Risk Factor for Adverse Outcomes in Patients With Predialysis Chronic Kidney Disease: A Prospective Cohort Study

OBJECTIVE

Both obesity and being underweight are risk factors for adverse outcomes in chronic kidney disease (CKD) patients. However, the effects of longitudinal weight changes on patients with predialysis CKD have not yet been studied. In this study, we analyzed the effects of weight change over time on the adverse outcomes in predialysis CKD population.

METHODS

Longitudinal data from a multicenter prospective cohort study (KNOW-CKD) were analyzed. In a total of 2,022 patients, the percent weight change per year were calculated using regression analysis and the study subjects were classified into five categories: group 1, ≤ -5%/year; group 2, -5< to ≤ -2.5%/year; group 3, -2.5< to <2.5%/year; group 4, 2.5≤ < 5%/year; and group 5, ≥5%/year. The incidences of end-stage renal disease (ESRD) and the composite outcome of cardiovascular disease (CVD) and death were calculated in each group and compared to group 3 as reference.

RESULTS

During a median 4.4 years of follow-up, 414 ESRD, and 188 composite of CVD and mortality events occurred. Both weight gain and loss were independent risk factors for adverse outcomes. There was a U-shaped correlation between the degree of longitudinal weight change and ESRD (hazard ratio 3.61, 2.15, 1.86 and 3.66, for group 1, 2, 4 and 5, respectively) and composite of CVD and death (hazard ratio 2.92, 2.15, 1.73 and 2.54, respectively), when compared to the reference group 3. The U-shape correlation was most prominent in the subgroup of estimated glomerular filtration rate <45 mL/min/1.73 m².

CONCLUSION

Both rapid weight gain and weight loss are associated with high risk of adverse outcomes, particularly in the advanced CKD.

Eight Days of Water-Only Fasting Promotes Favorable Changes in the Functioning of the Urogenital System of Middle-Aged Healthy Men

The aim of this study was to determine whether, after 8 days of water-only fasting, there are changes in the efficiency of the lower urinary tract, the concentration of sex hormones, and the symptoms of prostate diseases in a group of middle-aged men (n = 14). For this purpose, before and after 8 days of water-only fasting (subjects drank ad libitum moderately mineralized water), and the following somatic and blood concentration measurements were made: total prostate specific antigen (PSA-T), free prostate specific antigen (PSA-F), follicle stimulating hormone (FSH), luteotropic hormone (LH), prolactin (Pr), total testosterone (T-T), free testosterone (T-F), dehydroepiandrosterone (DHEA), sex hormone globulin binding (SHGB), total cholesterol (Ch-T), β-hydroxybutyrate (β-HB). In addition, prostate volume (PV), volume of each testis (TV), total volume of both testes (TTV), maximal urinary flow rate (Qmax), and International Prostate Symptom Score (IPSS) values were determined. The results showed that after 8 days of water-only fasting, Qmax and IPSS improved but PV and TTV decreased significantly. There was also a decrease in blood levels of PSA-T, FSH, P, T-T, T-F, and DHEA, but SHGB concentration increased significantly. These results indicate that 8 days of water-only fasting improved lower urinary tract functions without negative health effects.

Cardiovascular metabolic risk factors and glomerular filtration rate: a rural Chinese population study

METHODS

A total of 2426 study subjects from rural China aged 35 years and above (934 men and 1492 women) were enrolled in a cross-sectional survey. The eGFR calculation was based on the Modification of Diet in Renal Disease (MDRD) equation. The strength of the association between cardiovascular metabolic risk factors and eGFR was analyzed using a linear regression model.

RESULTS

Cardiovascular metabolic risk factors, including age, body weight, waist circumference, fasting plasma glucose (FPG), creatinine (Cr), high-density lipoprotein-cholesterol (HDL-C), total cholesterol (TC), triglyceride (TG), systolic pressure, and diastolic pressure, were associated with eGFR. Additionally, the eGFR level gradually decreased and showed a linear trend with the increase in metabolic syndrome risk factors.

CONCLUSION

Metabolic risk factors are correlated with a reduction in renal function and CKD.