Potassium intake, skeletal muscle mass, and effect modification by sex: data from the 2008-2011 KNHANES

A smartphone-based sensor for detection of iron and potassium in food and beverage samples

A novel approach for simultaneous detection of iron and potassium via a smartphone-based potentiometric method is proposed in this study. The screen printed electrodes were modified with carbon black nanomaterial and ion selective membrane including zinc (II) phtalocyanine as the ionophore. The developed Fe3+-selective electrode and K+-selective electrode exhibited detection limits of 1.0 × 10-6 M and 1.0 × 10-5 M for Fe3+ and K+ ions, respectively. The electrodes were used to simultaneously detect Fe3+ and K+ ions in apple juice, skim milk, soybean and coconut water samples with recovery values between 90%-100.5%, and validated against inductively coupled plasma-optical emission spectrometry. Due to the advantageous characteristics of the sensors and the portability of Near Field Communication potentiometer supported with a smartphone application, the proposed method offers sensitive and selective detection of iron and potassium ions in food and beverage samples at the point of need.

Association between sodium and potassium intake levels and body compositions of Chinese college students

BACKGROUND AND OBJECTIVES

To investigate the relationship between sodium (Na) and potassium (K) nutritional condition and body compositions in youth aiming to give target population reasonable diet recommendations.

METHODS AND STUDY DESIGN

The cross-sectional study was conducted involving 512 healthy youth aged 18 to 31 years from universities in Beijing. Food frequency questionnaire (FFQ) and bioelectrical impedance analyzer (BIA) were used to collect dietary intake information and body compositions.

RESULTS

There was an increasing tendency in fat-related indicators and muscle-related indicators of the dietary Na tertile group (p <0.05). Additionally, Weight, body mass index (BMI), waist circumference (WC), and muscle-related indicators increased with the dietary K tertile group (p <0.05). Across increasing tertiles of dietary Na intake, the odds ratio (OR) was increased significantly (p < 0.05) in fat-related indicators. On the contrary, with the increased dietary Na intake, the OR decreased (p < 0.05) in appendicular skeletal muscle mass index (ASMI) and body lean mass. As tertiles of dietary K intake increased, the OR in both skeletal muscle mass index (SMMI) and lean mass index (LMI) decreased.

CONCLUSIONS

High dietary Na is a risk factor for abnormal lipid distribution in college students. High dietary K can maintain skeletal muscle mass and reduce the risk of obesity. Na in the diet has a greater impact on the body composition of young people than K. Low dietary Na and high dietary K still need to be strengthened in science popularization and practice among more college students.

Higher dietary magnesium and potassium intake are associated with lower body fat in people with impaired glucose tolerance

Introduction

Obesity and diabetes are public health concerns worldwide, but few studies have examined the habitual intake of minerals on body composition in people with prediabetes.

Methods

In this prospective cross-sectional study, 155 Chinese subjects with IGT [median age: 59 (53-62) years, 58% female] had an assessment of body composition including body fat percentage, oral glucose tolerance tests (OGTT), Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and 3-day food records from nutritional programme analysis.

Results

Dietary intake of minerals was negatively correlated with body fat. People with obesity had the lowest daily consumption of iron median (IQR) 10.3 (6.9-13.3) mg, magnesium 224 (181-282) mg, and potassium 1973 (1563-2,357) mg when compared to overweight [10.5 (8.0-14.5) mg, 273 (221-335) mg, and 2,204 (1720-2,650) mg] and normal weight individuals [13.2 (10.0-18.6) mg, 313 (243-368) mg, and 2,295 (1833-3,037) mg] (p = 0.008, <0.0001, and 0.013 respectively). Amongst targeted minerals, higher dietary magnesium and potassium intake remained significantly associated with lower body fat after the adjustment of age, gender, macronutrients, fibre, and physical activity.

Conclusion

Dietary magnesium and potassium intake may be associated with lower body fat in people with impaired glucose tolerance. Inadequate dietary mineral intake may play contribute to obesity and metabolic disorders independent of macronutrients and fibre consumption.

Impact of Sodium Zirconium Cyclosilicate Therapy on Nutrition Status in Patients with Hyperkalemia

Background: Restriction of oral potassium intake is a necessary dietary intervention for managing chronic hyperkalemia. These dietary changes may have negative impacts on nutrition status, particularly in geriatric cohorts with multiple comorbidities. Sodium zirconium cyclosilicate (SZC) is a newly introduced potassium binder intended for patients with hyperkalemia. We aimed to investigate whether the improvements in hyperkalemia with SZC therapy and the liberation of potassium intake restriction may improve nutrition status in a primarily geriatric patient cohort with chronic hyperkalemia. Methods: Patients who were maintained on SZC therapy for at least 3 months were retrospectively studied. Following the initiation of SZC and improvement in hyperkalemia, instructions on the restriction of potassium intake were loosened according to the institutional protocol. The change in nutrition status during the 3 month therapeutic period using SZC was investigated by referencing the prognostic nutritional index score (PNI), geriatric nutritional risk index score (GNRI), and controlling nutritional status (CONUT) scores. Results: A total of 24 patients (median age 78 years, 58% men, median estimated glomerular filtration rate 29.8 mL/min//1.73 m2) were included. Serum potassium level decreased significantly from 5.4 (5.1, 5.9) to 4.4 (4.2, 4.9) mEq/L without any drug-related adverse events, including hypokalemia. Nutrition-related scores, including the PNI score, the GNRI score, and the CONUT score, improved significantly following 3 months of SZC therapy (p < 0.05 for all). Psoas muscle volume and average days for one movement also improved significantly during the therapeutic period (p < 0.05 for both). Conclusions: Mid-term SZC therapy and liberation of potassium intake restriction might improve nutrition status in geriatric patients with chronic hyperkalemia.

Estimation of skeletal muscle mass by bioimpedance and differences among skeletal muscle mass indices for assessing sarcopenia

BACKGROUND

It is crucial to assess age-related muscle mass changes and derived indices differences in geriatric medicine. We aimed to develop and validate four bioimpedance analysis (BIA) prediction equations against dual-energy X-ray absorptiometry (DEXA) and magnetic resonance image (MRI) in estimating skeletal muscle mass and to compare the differences among skeletal muscle mass indices, cutoff values, and corresponding prevalence rates of low muscle mass for assessing sarcopenia in Chinese adults.

METHODS

We measured the height (Ht), weight (Wt), appendicular lean mass (ALM) or skeletal muscle mass (ASM), total lean body mass (LBM) or skeletal muscle mass (TSM) obtained using DEXA or MRI, and a multi-frequency BIA (BCA _II;50, 250 kHz), in 371 adults aged 18.0-87.0 years. We also collected gender, age, Ht, Wt, and impedance indexes (Ht²/R₅₀, Ht²/R₂₅₀, R₅₀/Ht², R₂₅₀/Ht²) from 30,500 adults aged 18-96 years living in China. Multiple regression analyses were used to derive four prediction equations by BIA, and double cross-validation techniques and Bland-Altman analyses were used to test agreement. Various muscle mass indices and prevalence rates were depicted by line plots in regard to age trends.

RESULTS

Satisfactory results were found in the four prediction models as they had the larger R² (0.833-0.930) values and low SEE (1.409-2.335 kg) values. The predictive variables included impedance indexes (Ht²/R₅₀, R₅₀/Ht², R₂₅₀/Ht²), gender, age, Wt, and Ht. The corresponding prevalence rates of low muscle mass exhibited significant differences according to the various muscle mass indices adjusted for Ht, Wt, or body mass index (BMI), in addition to the cutoff values based on two standard deviations (2SD) of young people or the lower 20% of the study group.

CONCLUSIONS

The BIA equations have the potential to be applied as a practical method of quantifying skeletal muscle mass in Chinese adults. However, the operational methods that are most appropriate for determining the degree of low muscle mass that actually contributes to sarcopenia remains inconclusive.