The present study was carried out to evaluate the effects of okra extract supplementation on kidney function, glycaemic control, inflammation and gene expression in patients with diabetic nephropathy (DN). A total of sixty-four DN patients based on the inclusion and exclusion criteria were recruited in this triple-blind placebo-controlled randomised clinical trial. Participants were randomly allocated to receive a 125-mg capsule of dried okra extract (DOE) (n 32) or placebo (n 32) for 10 weeks. At the baseline and endpoint of the trial, kidney function, glycaemic indices, inflammation and gene expression were evaluated. Statistical analysis showed that fasting blood glucose, HbA1c and insulin resistance significantly reduced in the DOE group although between-group analysis did not show any significant difference. Also, no significant difference was observed in urine protein, urine creatinine and high-sensitivity C-reactive protein between the two groups. Furthermore, gene expression of PPAR-α, PPAR-γ, transforming growth factor-beta and Nrf-2 did not affect the end of the trial in comparison with the baseline. According to the present study, DOE did not have impressive effects on kidney function, inflammation, glycaemic management and gene expression in patients with DN.

Maternal protein restriction is often associated with structural and functional sequelae in offspring, particularly affecting growth and renal-cardiovascular function. However, there is little understanding as to whether hypertension and kidney disease occur because of a primary nephron deficit or whether controlling postnatal growth can result in normal renal-cardiovascular phenotypes. To investigate this, female Sprague-Dawley rats were fed either a low-protein (LP, 8.4% protein) or normal-protein (NP, 19.4% protein) diet prior to mating and until offspring were weaned at postnatal day (PN) 21. Offspring were then fed a non ‘growth’ (4.6% fat) which ensured that catch-up growth did not occur. Offspring growth was determined by weight and dual energy X-ray absorptiometry. Nephron number was determined at PN21 using the disector-fractionator method. Kidney function was measured at PN180 and PN360 using clearance methods. Blood pressure was measured at PN360 using radio-telemetry. Body weight was similar at PN1, but by PN21 LP offspring were 39% smaller than controls (Pdiet < 0.001). This difference was due to proportional changes in lean muscle, fat, and bone content. LP offspring remained smaller than NP offspring until PN360. In LP offspring, nephron number was 26% less in males and 17% less in females, than NP controls (Pdiet < 0.0004). Kidney function was similar across dietary groups and sexes at PN180 and PN360. Blood pressure was similar in LP and NP offspring at PN360. These findings suggest that remaining on a slow growth trajectory after exposure to a suboptimal intrauterine environment does not lead to the development of kidney dysfunction and hypertension.

Dietary supplements have been increasingly used by gym users and are often consumed without the guidance of a health professional. Moreover, the indiscriminate supplements use can have adverse health effects, such as changes in liver and kidney function. The aim of this study was to verify the association between dietary supplements intake with alterations in the liver and kidney function among gym users. A cross-sectional study was conducted with 594 gym users (mean age 37 (sd 14) years, 55·2 % women) from a city in southern Brazil. A questionnaire was used to evaluate the use of dietary supplements. The markers of the liver (alanine aminotransferase, aspartate aminotransferase (AST), alkaline phosphatase, γ-glutamyltransferase) and renal (creatinine and urea) function were also evaluated on a subsample of the study population. Data were analysed by binary logistic regression, adjusted for sex, age and education. The prevalence of dietary supplement intake was 36·0 %. Individuals who intake dietary supplements showed a higher prevalence to present slight alterations in the AST enzyme and in the urea after adjustments for potential confounders. In conclusion, the use of dietary supplement was associated with slight alterations in AST enzyme and in the urea among gym users. These findings show the importance of using supplements correctly, especially with guidance from professionals trained to avoid possible risks to health.

Kidney function affects amino acid metabolism and vitamin status. The aims of the present study were to investigate urine and plasma concentrations of amino acids as well as plasma vitamin status in rats with impaired renal function (Zucker fa/fa rats) and in rats with normal kidney function (Long-Evans rats), and to explore the effects of salmon intake on these parameters and potential biomarkers of salmon intake in both rat strains. Male rats were fed diets with casein as sole protein source (control diet) or 25 % protein from baked salmon and 75 % casein for 4 weeks. Urine concentrations of markers of renal function and most amino acids and plasma concentrations of most vitamins were higher, and plasma concentrations of several amino acids including arginine, total glutathione and most tryptophan metabolites were lower in Zucker fa/fa rats compared with Long-Evans rats fed the control diet. Concentrations of kidney function markers were lower after salmon intake only in Zucker fa/fa rats. A trend towards lower urine concentrations of amino acids was seen in both rat strains fed the salmon diet, but this was more pronounced in Long-Evans rats and did not reflect the dietary amino acid content. Urine 1-methylhistidine, 3-methylhistidine, trimethylamineoxide and creatine concentrations, and plasma 1-methylhistidine and creatine concentrations were higher after salmon intake in both rat strains. To conclude, concentrations of amino acids in urine and plasma as well as vitamin status were different in Zucker fa/fa and Long-Evans rats, and the effects of salmon intake differed by rat strain for some of these parameters.

Obesity increases the risk for developing kidney disease, and protection of kidneys through changes in diet should be investigated. Fish intake has been associated with reduced risk of developing kidney disease; therefore, we wanted to investigate whether cod protein intake could prevent or delay the development of kidney damage in an obese rat model that spontaneously develops proteinuria and focal segmental glomerulosclerosis. The aim of the study was to investigate any effects of cod protein intake on established markers of kidney function, amino acid composition, protein utilisation and growth in obese Zucker fa/fa rats in the early stage of decreased renal function. Male obese Zucker fa/fa rats (HsdOla:Zucker-Lepr) were fed cod muscle proteins in an amount corresponding to 25 % of dietary protein, with the remaining protein from a casein/whey mixture (COD diet). A control group was fed a diet with a casein/whey mixture as the only protein source (CAS diet). The intervention started when rats were 9–10 weeks old, and the rats were fed these diets for 4 weeks. At the end of the study, rats fed the COD diet had lower urine concentration of cystatin C, T-cell immunoglobulin mucin-1 (TIM-1), amino acids, carbamide, uric acid and ammonium and higher concentrations of creatine, trimethylamine N-oxide, 1-methylhistidine and 3-methylhistidine, lower kidney concentration of TIM-1 and showed better growth when compared with the CAS group. To conclude, cod protein may have the potential to delay the development of kidney damage in young obese Zucker rats and to improve protein utilisation and growth.

The purpose of this study was primarily to evaluate the association of total fibre intake with the risk of incident chronic kidney disease (CKD). We also evaluated the association of dietary fibre from fruits, vegetables, cereals and legumes with the incidence of CKD in a population-based prospective study. We followed up 1630 participants of the Tehran Lipid and Glucose Study for 6·1 years, who were initially free of CKD. Baseline diet was assessed by a valid and reliable FFQ. Estimated glomerular filtration rate (eGFR) was calculated, using the Modification of Diet in Renal Disease Study equation, and CKD was defined as eGFR <60 ml/min per 1·73 m2. OR using multivariable logistic regression was reported for the association of incident CKD with tertiles of dietary fibre intake. After adjustment for age, sex, smoking, total energy intake, physical activity, diabetes and using angiotensin-converting-enzyme inhibitor, the OR for subjects in the highest compared with the lowest tertile of total fibre intake was 0·47 (95 % CI 0·27, 0·86). In addition, for every 5 g/d increase in total fibre intake, the risk of incident CKD decreased by 11 %. After adjusting for potential confounders, OR for participants in the highest compared with the lowest tertile of fibre from vegetables was 0·63 (95 % CI 0·43, 0·93) and from legumes it was 0·68 (95 % CI 0·47, 0·98). We observed inverse associations between total fibre intake and risk of incident CKD, which demonstrate that high fibre intake, mainly from legumes and vegetables, may reduce the occurrence of CKD.

Exposure of growing rabbits to heat stress during summer adversely affects their performance leading to major production losses. A total number of 48 rabbits, unsexed V-line weaned rabbits, were randomly divided into four experimental groups, temperature ranged from high at 32°C to low at 23°C. Animals of the 2nd, 3rd and 4th group were individually orally given 200, 400 or 800 mg royal jelly (RJ)/kg BW once a week, respectively, to evaluate RJ ability to reduce physiological strain resulted from heat stress. Weekly BW gain increased by 10.4, 11.8 and 10.8%, and feed conversion ratio was significantly improved by 20, 24 and 18% with RJ treatments. Serum total protein, albumin and globulin increased, whereas serum total lipids, cholesterol and triglycerides decreased with RJ treatments. Creatinine was reduced by 21, 30 and 18% and uric acid by 14, 25 and 18% compared with the heat stressed control with the three doses of RJ. Glucose level increased significantly to reach 116, 125, and 120% of heat stressed control. Calcium, phosphorus and alkaline phosphatase increased significantly with RJ treatments indicating the occurrence of active bone deposition. Thyroid hormone levels increased significantly to reach 108, 111, and 112% of heat stressed control rabbits with the three doses of RJ, counteracting the hypothyroid state resulted from heat stress. It can be concluded that RJ administration to heat stressed growing rabbits can reduce physiological strain resulted from heat stress.

Habitual coffee consumption is associated with the prevention of type 2 diabetes, which often accompanies diabetic nephropathy. However, the relationship between coffee consumption and kidney function is unclear. Therefore, we investigated the associations between habitual coffee consumption and kidney function and damage assessed by the estimated glomerular filtration rate (eGFR) and proteinuria using dipstick urinalysis, respectively, in a cross-sectional study of 342 apparently healthy adults. Habitual coffee consumption was defined as drinking one or more cups of coffee per d. eGFR in coffee consumers (n 182; 80·1 (sd 15·0) ml/min per 1·73 m2) was significantly higher than that in non-coffee consumers (n 160; 76·9 (sd 12·6) ml/min per 1·73 m2) (P < 0·05). Multivariate logistic analysis showed that, compared with non-coffee consumption, coffee consumption was significantly associated with normal or increased eGFR (NIGFR) ( ≥ 90 ml/min per 1·73 m2), but not proteinuria, which was not attenuated, even after adjustment for age, sex, smoking, tea consumption and other cardiovascular risks (OR 2·91; 95 % CI 1·51, 5·61; P = 0·001). When we took into account eGFR measured 1 year before in a subgroup of the subjects (n 262), coffee consumption (n 142) had a significant relationship with eGFR, which was consistently higher with a difference of 4·0 ml/min per 1·73 m2 compared with non-coffee consumption (P = 0·01; two-way repeated ANOVA). Similar associations were observed in both sexes when data were reanalysed according to sex. In conclusion, our findings suggest that habitual coffee consumption is associated with NIGFR independently of clinical confounders. Further studies are needed to confirm this association and to explore whether the effect of coffee consumption on eGFR is beneficial for the kidney.