Project description:Recent interest in protein intake per meal is observed in studies that have reported the protein intake patterns in different countries; however, comparisons of these data are lacking. We aimed to compare protein intake patterns and the percentage of inadequate protein intake (IPI) per day and meal in older adults from different countries. We acquired data of protein intake in older adults from four countries (Mexico, United States of America, Germany, and United Kingdom). We compared protein intake (per day and meal), IPI per day and meal, and the number of meals with an adequate protein content among countries. The IPI per day significantly differed among countries for <0.8 and <1.0 (both p < 0.001), but not for <1.2 g/kg/d (p = 0.135). IPI per meal (<30 g/meal) did not differ among countries at breakfast (p = 0.287) and lunch (p = 0.076) but did differ at dinner (p < 0.001). Conversely, IPI per meal (<0.4 g/kg/meal) significantly differed among countries at breakfast, lunch, and dinner (all p < 0.001). The percentage of participants that ate ≥30 g/meal or ≥0.4 g/kg/meal at zero, one, and two or three meals per day significantly differed among countries (all p < 0.05). IPI at breakfast and lunch (<30 g/meal) was a common trait in the analyzed samples and might represent an opportunity for nutritional interventions in older adults in different countries.
Project description:BackgroundThe basolateral potassium channel in the distal convoluted tubule (DCT), comprising the inwardly rectifying potassium channel Kir4.1/Kir5.1 heterotetramer, plays a key role in mediating the effect of dietary potassium intake on the thiazide-sensitive NaCl cotransporter (NCC). The role of Kir5.1 (encoded by Kcnj16) in mediating effects of dietary potassium intake on the NCC and renal potassium excretion is unknown.MethodsWe used electrophysiology, renal clearance, and immunoblotting to study Kir4.1 in the DCT and NCC in Kir5.1 knockout (Kcnj16-/- ) and wild-type (Kcnj16+/+ ) mice fed with normal, high, or low potassium diets.ResultsWe detected a 40-pS and 20-pS potassium channel in the basolateral membrane of the DCT in wild-type and knockout mice, respectively. Compared with wild-type, Kcnj16-/- mice fed a normal potassium diet had higher basolateral potassium conductance, a more negative DCT membrane potential, higher expression of phosphorylated NCC (pNCC) and total NCC (tNCC), and augmented thiazide-induced natriuresis. Neither high- nor low-potassium diets affected the basolateral DCT's potassium conductance and membrane potential in Kcnj16-/- mice. Although high potassium reduced and low potassium increased the expression of pNCC and tNCC in wild-type mice, these effects were absent in Kcnj16-/- mice. High potassium intake inhibited and low intake augmented thiazide-induced natriuresis in wild-type but not in Kcnj16-/- mice. Compared with wild-type, Kcnj16-/- mice with normal potassium intake had slightly lower plasma potassium but were more hyperkalemic with prolonged high potassium intake and more hypokalemic during potassium restriction.ConclusionsKir5.1 is essential for dietary potassium's effect on NCC and for maintaining potassium homeostasis.
Project description:Objective: To examine the association between intakes of sodium and potassium and the ratio of sodium to potassium and incident myocardial infarction and stroke. Design, Setting and Participants: Prospective cohort study of 180,156 Veterans aged 19 to 107 years with plausible dietary intake measured by food frequency questionnaire (FFQ) who were free of cardiovascular disease (CVD) and cancer at baseline in the VA Million Veteran Program (MVP). Main outcome measures: CVD defined as non-fatal myocardial infarction (MI) or acute ischemic stroke (AIS) ascertained using high-throughput phenotyping algorithms applied to electronic health records. Results: During up to 8 years of follow-up, we documented 4090 CVD cases (2499 MI and 1712 AIS). After adjustment for confounding factors, a higher sodium intake was associated with a higher risk of CVD, whereas potassium intake was inversely associated with the risk of CVD [hazard ratio (HR) comparing extreme quintiles, 95% confidence interval (CI): 1.09 (95% CI: 0.99−1.21, p trend = 0.01) for sodium and 0.87 (95% CI: 0.79−0.96, p trend = 0.005) for potassium]. In addition, the ratio of sodium to potassium (Na/K ratio) was positively associated with the risk of CVD (HR comparing extreme quintiles = 1.26, 95% CI: 1.14−1.39, p trend < 0.0001). The associations of Na/K ratio were consistent for two subtypes of CVD; one standard deviation increment in the ratio was associated with HRs (95% CI) of 1.12 (1.06−1.19) for MI and 1.11 (1.03−1.19) for AIS. In secondary analyses, the observed associations were consistent across race and status for diabetes, hypertension, and high cholesterol at baseline. Associations appeared to be more pronounced among participants with poor dietary quality. Conclusions: A high sodium intake and a low potassium intake were associated with a higher risk of CVD in this large population of US veterans.
Project description:(1) Background: Dietary potassium intake is positively associated with reduction of cardiovascular risk. Several data are available on the relationship between dietary potassium intake, diabetes risk and glucose metabolism, but with inconsistent results. Therefore, we performed a meta-analysis of the prospective studies that explored the effect of dietary potassium intake on the risk of diabetes to overcome these limitations. (2) Methods: A random-effects dose-response meta-analysis was carried out for prospective studies. A potential non-linear relation was investigated using restricted cubic splines. (3) Results: A total of seven prospective studies met the inclusion criteria. Dose-response analysis detected a non-linear relationship between dietary potassium intake and diabetes risk, with significant inverse association starting from 2900 mg/day by questionnaire and between 2000 and 5000 mg/day by urinary excretion. There was high heterogeneity among studies, but no evidence of publication bias was found. (4) Conclusions: The results of this meta-analysis indicate that habitual dietary potassium consumption is associated with risk of diabetes by a non-linear dose-response relationship. The beneficial threshold found supports the campaigns in favour of an increase in dietary potassium intake to reduce the risk of morbidity and mortality. Further studies should be carried out to explore this topic.
Project description:ObjectivesAmong hemodialysis patients, clinical practice guidelines recommend dietary potassium restriction given concerns about potential hyperkalemia leading to malignant arrhythmias and mortality. However, there are sparse data informing recommendations for dietary potassium intake in this population. We thus sought to examine the relationship between dietary potassium intake and death risk in a prospective cohort of hemodialysis patients.Design and methodsAmong 415 hemodialysis patients from the prospective "Malnutrition, Diet, and Racial Disparities in Chronic Kidney Disease" cohort recruited across 16 outpatient dialysis clinics, information regarding dietary potassium intake was obtained using Food Frequency Questionnaires administered over October 2011 to March 2015. We first examined associations of baseline dietary potassium intake categorized as tertiles with mortality risk using Cox regression. We then examined clinical characteristics associated with low dietary potassium intake (defined as the lowest tertile) using logistic regression.ResultsIn expanded case-mix Cox analyses, patients whose dietary potassium intake was in the lowest tertile had higher mortality (ref: highest tertile) (adjusted hazard ratio 1.74, 95% confidence interval 1.14-2.66). These associations had even greater magnitude of risk following adjustment for laboratory and nutritional covariates (adjusted hazard ratio 2.65, 95% confidence interval 1.40-5.04). In expanded case-mix restricted cubic spline analyses, there was a monotonic increase in mortality risk with incrementally lower dietary potassium intake. In expanded case-mix logistic regression models, female sex; higher serum bicarbonate; and lower dietary energy, protein, and fiber intake were associated with low dietary potassium intake.ConclusionsIn a prospective cohort of hemodialysis patients, lower dietary potassium intake was associated with higher mortality risk. These findings suggest that excessive dietary potassium restriction may be deleterious in hemodialysis patients, and further studies are needed to determine the optimal dietary potassium intake in this population.
Project description:Aging has been implicated in the alteration of taste acuity. Diet can affect taste sensitivity. We aimed to investigate the types of tastes altered in elderly Korean people and factors associated with taste alteration in relation to dietary intake and other factors. Elderly participants (≥65 years) and young adults were assessed to determine their recognition thresholds (RT) for sweet, salty, bitter, sour, and umami tastes. Elderly participants were further surveyed for dietary intake and non-nutritional factors. Five taste RTs were correlated with age, but only four taste RTs, except sweetness, differed between the elderly participants and young adults. Inadequate intake of iron, thiamin, folic acid, zinc, and phosphorus among the elderly participants was related to elevated taste RT levels, except for bitter taste. In both correlation and regression analyses, only salty and sour RTs were associated with energy, iron, thiamin, fiber, vitamin C, and riboflavin levels in the elderly participants. The elderly participants' taste RTs exhibited strong associations with quality of life (QOL) but showed partial relationships with physical activity, number of medicine intakes, social gatherings, and education. Taste sensitivity may decrease with age, which is further influenced by insufficient dietary intake, especially iron and thiamin, and QOL.
Project description:BackgroundWhile numerous studies have reported associations between low dietary potassium intake and adverse clinical outcomes, methods to estimate potassium intake, mainly self-reported dietary measures and urinary potassium excretion, entail certain limitations. Self-reported measures are subject to underreporting and overreporting. Urinary potassium excretion is affected by multiple factors including renal function. Revealing the degree of bias inherent in these measures would help accurately assess potassium intake and its association with disease risk. We aim to summarize evidence on the strength of the associations between potassium intake estimated from 24-h urinary potassium excretion and potassium intake estimated from self-reported dietary measures or objective quantification methods in populations with different kidney function levels and age groups. We also aim to identify factors that affect the association strength.MethodsWe will search for potentially eligible studies that examined associations between self-reported potassium intake, 24-h urinary potassium excretion, and objectively quantified potassium intake, using MEDLINE (PubMed), Embase, Web of Science, and Scopus. Studies on children, adolescents, adults, and the elderly are eligible. Studies of patients on dialysis will be excluded. Collective study results, including a meta-analysis, will be synthesized if an adequate number of studies examining similar dietary potassium intake estimation methods are found. Analyses will be performed separately according to age groups and renal function. For the meta-analysis, fixed-effects or random-effect models will be employed depending on the degree of study heterogeneity to combine across studies the correlation coefficient, ratio, or standardized mean difference for potassium intake, comparing dietary potassium intake based on self-reported or objectively quantified methods and intake based on 24-h urinary potassium excretion. The degree of heterogeneity among included studies will be examined by calculating I2 statistics. To investigate sources of study heterogeneity, random-effects meta-regression analyses will be performed.DiscussionRevealing the strength of the association between dietary and urinary measures in populations with different levels of kidney function and age groups will enhance researchers' and clinicians' ability to interpret studies that utilize these measures and help establish a more solid evidence base for the role of potassium intake in changing chronic disease risk. Identifying factors that modify the associations between these measures may aid in developing predictive models to estimate actual potassium intake.Systematic review registrationPROSPERO CRD42022357847.
Project description:BackgroundIn healthy adults, higher dietary potassium intake is recommended given that potassium-rich foods are major sources of micronutrients, antioxidants, and fiber. Yet among patients with advanced kidney dysfunction, guidelines recommend dietary potassium restriction given concerns about hyperkalemia leading to malignant arrhythmias and mortality.ObjectivesGiven sparse data informing these recommendations, we examined associations of dietary potassium intake with mortality in a nationally representative cohort of adults from the NHANES.MethodsWe examined associations between daily dietary potassium intake scaled to energy intake (mg/1000 kcal), ascertained by 24-h dietary recall, and all-cause mortality among 37,893 continuous NHANES (1999-2014) participants stratified according to impaired and normal kidney function (estimated glomerular filtration rates <60 and ≥60 mL · min-1 · 1.73 m-2, respectively) using multivariable Cox models. We also examined the impact of the interplay between dietary potassium, source of potassium intake (animal- compared with plant-based sources), and coexisting macronutrient and mineral consumption upon mortality.ResultsAmong participants with impaired and normal kidney function, the lowest tertile of dietary potassium scaled to energy intake was associated with higher mortality (ref: highest tertile) [adjusted HR (aHR): 1.18; 95% CI: 1.02, 1.38 and aHR: 1.17; 95% CI: 1.06, 1.28, respectively]. Compared with high potassium intake from plant-dominant sources, participants with low potassium intake from animal-dominant sources had higher mortality irrespective of kidney function. Among participants with impaired kidney function, pairings of low potassium intake with high protein, low fiber, or high phosphorus consumption were each associated with higher death risk.ConclusionsLower dietary potassium scaled to energy intake was associated with higher mortality, irrespective of kidney function. There was also a synergistic relation of higher potassium intake, plant-based sources, and macronutrient/mineral consumption with survival. Further studies are needed to elucidate pathways linking potassium intake and coexisting dietary factors with survival in populations with and without chronic kidney disease.