Multiple measurements of the urinary sodium-to-potassium ratio strongly related home hypertension: TMM Cohort Study

Relationships of Fat Mass Index and Fat-Free Mass Index with Low-Density Lipoprotein Cholesterol Levels in the Tohoku Medical Megabank Community-Based Cohort Study

AIMS

Although fat mass (FM) and fat-free mass (FFM) have an impact on lipid metabolism, the relationship between different body composition phenotypes and lipid profiles is still unclear. By dividing the FM and FFM by the square of the height, respectively, the fat mass index (FMI) and fat-free mass index (FFMI) can be used to determine the variations in body composition. This study aimed to investigate the relationship of combined FMI and FFMI with low-density lipoprotein cholesterol (LDL-C) levels.

METHODS

This cross-sectional study comprised 5,116 men and 13,630 women without cardiovascular disease and without treatment for hypertension, and diabetes. Following sex-specific quartile classification, FMI and FFMI were combined into 16 groups. Elevated LDL-C levels were defined as LDL-C ≥ 140 mg/dL and/or dyslipidemia treatment. Multivariable logistic regression models were used to examine the relationships between combined FMI and FFMI and elevated LDL-C levels.

RESULTS

Overall, elevated LDL-C levels were found in 1,538 (30.1%) men and 5,434 (39.9%) women. In all FFMI subgroups, a higher FMI was associated with elevated LDL-C levels. Conversely, FFMI was inversely associated with elevated LDL-C levels in most FMI subgroups. Furthermore, the groups with the highest FMI and lowest FFMI had higher odds ratios for elevated LDL-C levels than those with the lowest FMI and highest FFMI.

CONCLUSIONS

Regardless of FFMI, FMI was positively associated with elevated LDL-C levels. Conversely, in the majority of FMI subgroups, FFMI was inversely associated with elevated LDL-C levels.

Relationship between traditional risk factors for hypertension and systolic blood pressure in the Tohoku Medical Megabank Community-based Cohort Study

Risk factors for hypertension have been emphasized in the Japanese Society of Hypertension Guidelines for the Management of Hypertension. However, large-scale studies on the association of smoking, potassium excretion, and gamma-glutamyl transferase level with BP in the Japanese population are limited. We conducted a cross-sectional study to examine the association between hypertension risk factors and systolic blood pressure in the Tohoku Medical Megabank Community-based Cohort Study (23,446 men and 38,921 women aged ≥20 years). A model adjusted for age, body mass index, smoking status, drinking status, estimated daily salt intake, potassium excretion, (or urinary sodium-to-potassium ratio), gamma-glutamyl transferase, physical activity, education level, status of damage to homes during the Great East Japan Earthquake, and residential areas was used. The average age and systolic blood pressure were 62.5 (10.3) years for men and 59.6 (11.3) years for women, 128.9 (16.7) mmHg for men and 124.7 (17.5) mmHg for women, respectively. Body mass index estimated daily salt intake, urinary sodium-to-potassium ratio and gamma-glutamyl transferase levels were positively associated with systolic blood pressure. Compared with never-drinkers, current drinkers who consumed 23-45 g/day and ≥46.0 g/day had significantly increased systolic blood pressure. Conversely, current smokers (1-10 cigarettes/day and 11-20 cigarettes/day) were inversely associated with systolic blood pressure compared to never-smokers. Overall, systolic blood pressure was associated with gamma-glutamyl transferase and hypertension risk factors, including body mass index, alcohol consumption, estimated daily salt intake, urinary sodium-to-potassium ratio, and potassium excretion. Our findings support the notion that lifestyle modifications should be attempted to prevent hypertension.

Association of Central Blood Pressure and Carotid Intima Media Thickness with New-Onset Hypertension in People with High Normal Blood Pressure

AIM

People with high normal blood pressure (BP) have a higher risk of cardiovascular events than those with normal BP; therefore, progression to hypertension (HT) should be prevented. We aimed to assess the HT risk using central BP and carotid intima media thickness (CIMT) in people with high normal BP.

METHODS

This prospective cohort study used the Tohoku Medical Megabank Community-Based Project Cohort Study (conducted from 2013 in Miyagi Prefecture in Japan). The participants had a high normal BP, defined as a systolic BP of 120-139 mmHg and diastolic BP ＜90 mmHg using brachial BP measurement during the baseline survey. The outcome was new-onset HT during the secondary survey, conducted four years after the baseline survey.

RESULTS

Overall, 4,021 participants with high normal BP during the baseline survey, with an average age of 58.7 years, were included; 1,030 (26%) were diagnosed with new-onset HT during the secondary survey, 3.5±0.7 years after the baseline survey. The multivariable odds ratio (95% confidence interval) for HT in the highest versus lowest quartile of central BP was 1.7 (1.2-2.4, p=0.0030), and that of CIMT was 1.8 (1.4-2.4, p＜0.001). Subgroup analysis according to age (＜60 and ≥ 60 years) and sex revealed that the central BP was influential in groups with younger age and female individuals; CIMT was influential in all groups.

CONCLUSIONS

Higher central BP and thicker CIMT at the baseline were correlated with new-onset HT in individuals with high normal BP, independent of brachial systolic BP and other cardiovascular risk factors.

Interaction of Dietary Sodium-to-potassium Ratio and Dinner Energy Ratio on Prevalence of Hypertension in Inner Mongolia, China

BACKGROUND

Hypertension is one of the most common chronic diseases, and dietary factors play an important role in hypertension. We examined the interaction of dietary sodium-to-potassium (Na/K) ratio and dinner energy ratio on hypertension.

METHODS

We conducted this study using data from the cross-sectional National Survey for Nutrition and Adult Chronic Disease in 2015 in Inner Mongolia, China. Dietary data were collected using 24-hour diet records with food weights across 3 consecutive days. Logistic regression was used to determine the interaction of dinner energy ratio and dietary Na/K ratio on hypertension.

RESULTS

A total of 1,861 participants were included in this study, and 914 individuals were hypertensive (49.1%). Dinner energy ratio and high dietary Na/K ratio were independently related to high prevalence of hypertension. A formal test showed that dinner energy ratio interacted significantly with dietary Na/K ratio on hypertension (P < 0.001), with an adjusted odds ratio (OR) of 1.119 (95% confidence interval [CI], 1.040-1.203). Participants whose dinner energy ratio greater than 39.1% and dietary Na/K ratio of 3.625-6.053 had the highest OR of hypertension prevalence, with an adjusted OR of 2.984 (95% CI, 1.758-5.066), compared with participants with dinner energy ratio of 30.2-39.1%, and dietary Na/K ratio less than 2.348.

CONCLUSION

Our study highlighted the interactive effect of dinner energy ratio and dietary Na/K ratio on hypertension among adults in Inner Mongolia. We advocated a balanced diet (dinner energy ratio not small or large) and a low dietary Na/K ratio for reducing the prevalence of hypertension.

Carotid Intima Media Thickness and Risk Factor for Atherosclerosis: Tohoku Medical Megabank Community-Based Cohort Study

AIM

We examined the association between the carotid intima medica thickness (cIMT) and risk factors for atherosclerosis based on the Japan Atherosclerosis Society 2022 Atherosclerosis Prevention Guideline.

METHODS

Using data from the Tohoku Medical Megabank Community-based Cohort Study, we performed a cross-sectional study that enrolled 13,366 participants (age ≥ 20 years) with an analysis of covariance to assess associations between cIMT and risk factors for atherosclerosis. The maximum common carotid artery was measured using high-resolution B-mode ultrasound. Analysis was conducted in the model adjusted for age, sex, smoking status, drinking status, body mass index (BMI), systolic blood pressure (SBP), glycated hemoglobin (HbA1c), high-density lipoprotein-cholesterol (HDL-C), non-high-density lipoprotein-cholesterol (non-HDL-C), and height.

RESULTS

In this study cohort, the average age and cIMT were 57.3 (13.8) years and 0.61 (0.13) mm, respectively, which included 3,988 males (29.8%). Males had a higher cIMT than did the females. Age, height, BMI, SBP, HbA1c, and non-HDL-C were positively associated with cIMT. HDL-C was inversely associated with cIMT. Compared with never drinkers, current drinkers (≥ 46.0 g/day) had a significantly decreased cIMT.

CONCLUSIONS

The cIMT was associated with atherosclerosis risk factors including age, sex, BMI, SBP, HbA1c, non-HDL-C, and HDL-C, and adequate control of risks in high-risk individuals might be required to prevent atherosclerotic cardiovascular diseases.

The Association of Lung Function and Carotid Intima-Media Thickness in a Japanese Population: The Tohoku Medical Megabank Community-Based Cohort Study

AIM

Impaired lung function is associated with atherosclerotic vascular events. Carotid intima-media thickness (cIMT) is a marker for subclinical atherosclerosis. However, few studies have examined the association between lung function and cIMT among never smokers or individuals stratified by age. We investigated the association between lung function and cIMT in the Japanese population.

METHODS

We conducted a cross-sectional study of 3,716 men and 8,765 women aged 20 years or older living in Miyagi Prefecture, Japan. Lung function was evaluated using forced expiratory volume at 1 s (FEV1) and forced vital capacity (FVC) was measured using spirometry. The maximum common carotid artery was measured using high-resolution B-mode ultrasound. An analysis of covariance was used to assess associations between lung function and cIMT and adjusted for potential confounders. A linear trend test was conducted by scoring the categories from 1 (lowest) to 4 (highest) and entering the score as a continuous term in the regression model.

RESULTS

After adjusting for potential confounders including passive smoking, lower FEV1 and FVC were associated with higher cIMT in both men and women (P＜0.001 for linear trend). This association was confirmed even when we restricted our study to never smokers. Furthermore, even when we stratified by age, an inverse association between lung function and cIMT was confirmed in middle-aged (40-64 years) and elderly participants (65-74 years).

CONCLUSIONS

Lower lung function was associated with higher cIMT in the Japanese population independent of age and smoking. Assessment of atherosclerosis or lung function may be required for individuals with lower lung function or atherosclerosis.

Relationship between the urinary Na/K ratio, diet and hypertension among community-dwelling older adults

The association between the urinary sodium (Na)/potassium (K) ratio and hypertension is well recognized. We investigated whether the urinary Na/K ratio might be associated with hypertension in community-dwelling older adults and whether the association was influenced by habitual dietary patterns. We enrolled a total of 684 older adults (mean age, 76.8 years) and conducted health examinations at Kusatsu, Japan, in 2021. The urinary Na/K ratio was found to be independently associated with systolic blood pressure (SBP) (p < 0.0001), years of education (p = 0.0027), number of cohabitants (p = 0.0175), estimated glomerular filtrate rate (eGFR) (p = 0.0244), and Geriatric Depression Scale short-version (GDS15) score (p = 0.0366). In addition, an unsupervised hierarchical clustering analysis revealed a spectrum of habitual dietary patterns for higher and lower values of the urinary Na/K ratio. The decision tree indicated that the urinary Na/K ratio was associated with the history of milk consumption. A positive history of daily milk consumption predicted a mean urinary Na/K ratio of 2.8, and a negative history of daily milk consumption predicted a mean urinary Na/K ratio of 3.3. Furthermore, the frequency of fruit and vegetable consumption also predicted the urinary Na/K ratio. The relationship between the urinary Na/K ratio and hypertension was influenced by the frequency of consumption of milk, fruits, and vegetables in the subjects. This finding might be due to the influence of education and/or depression. The results suggested the importance of nutritional education in the development of hypertension.

Association between lung function and hypertension and home hypertension in a Japanese population: the Tohoku Medical Megabank Community-Based Cohort Study

BACKGROUND

Although several studies have shown an inverse association between lung function and hypertension, few studies have examined the association between lung function and hypertension among never-smokers, and no study has investigated the association between lung function and home hypertension. We investigated the associations between lung function and hypertension in a Japanese population.

INDIVIDUALS AND METHODS

We conducted a cross-sectional study of 3728 men and 8795 women aged 20 years or older living in Miyagi Prefecture, Japan. Lung function was assessed using forced expiratory volume at 1 s (FEV 1 ) and forced vital capacity (FVC), measured by spirometry. Hypertension was defined as a casual blood pressure at least 140/90 mmHg and/or self-reported treatment for hypertension. Home hypertension was defined as morning home blood pressure at least 135/85 mmHg and/or self-reported treatment for hypertension. Multivariate logistic regression models adjusted for potential confounders were used to assess the association between lung function and hypertension.

RESULTS

The mean ages (±SD) of men and women were 60.1 (±14.0) years and 56.2 (±13.4) years, respectively, and 1994 (53.5%) men and 2992 (34.0%) women had hypertension. In the multivariable models, FEV 1 and FVC were inversely associated with hypertension. Inverse associations between lung function and hypertension were observed even among never-smokers. Furthermore, reduced lung function was associated with higher prevalence of home hypertension in men and women.

CONCLUSION

Reduced lung function was associated with higher prevalence of hypertension, independent of smoking status. Assessment of the lung function or blood pressure may be required in individuals with reduced lung function or hypertension.

Association between urinary sodium-to-potassium ratio and home blood pressure and ambulatory blood pressure: the Ohasama study

OBJECTIVE

No studies have demonstrated the association between urinary sodium-to-potassium (Na/K) ratio and all out-of-office blood pressure (BP) [home morning and evening BP (self-measured at home), and 24-h, daytime, and night-time ambulatory BP] in the same cohort. We aimed to assess, which type of out-of-office BP is more strongly associated with urinary Na/K ratio in the general population.

METHODS

This cross-sectional study was conducted in the general population of Ohasama, Japan. Home and ambulatory BP levels were measured, and 24-h urine samples were obtained from 875 participants (men, 25.5%; mean age, 60.1 years). The urinary Na/K ratio in the 24-h urine samples was calculated.

RESULTS

The median (interquartile range) urinary Na/K ratio was 4.19 (3.36-5.26). Significant positive trends of home morning, home evening, 24-h, and daytime SBP were observed across quartiles of urinary Na/K ratio (trend P ≤ 0.041; adjusted mean values between Q1 and Q4 of urinary Na/K ratio: 121.0-125.5 mmHg for home morning, 120.1-123.8 mmHg for home evening, 121.6-123.4 mmHg for 24-h, 127.5-129.5 mmHg for daytime). Urinary Na/K ratio was not significantly associated with office or night-time SBP and nocturnal BP fall (trend P ≥ 0.13). In the model with both home morning or evening SBP and daytime SBP, only home SBP was significantly associated with urinary Na/K ratio (P ≤ 0.048 for home SBP).

CONCLUSION

These findings suggest that urinary Na/K ratio might be more strongly associated with home BP than with 24-h and daytime BP but was not associated with night-time BP.

Consideration of the reference value and number of measurements of the urinary sodium-to-potassium ratio based on the prevalence of untreated home hypertension: TMM Cohort Study

The sodium-to-potassium (Na/K) ratio is known to be associated with blood pressure (BP). However, no reference value has been established since the urinary Na/K (uNa/K) ratio is known to have diurnal and day-to-day variations. Therefore, we investigated the number of days required to yield a better association between the morning uNa/K ratio and home BP (HBP) and determined a morning uNa/K ratio value that can be used as a reference value in participants who are not taking antihypertensive medication. This was a cross-sectional study using data from the Tohoku Medical Megabank Project Cohort Study. A total of 3122 participants borrowed HBP and uNa/K ratio monitors for 10 consecutive days. We assessed the relationship between the morning uNa/K ratio from 1 day to 10 days and home hypertension (HBP ≥ 135/85 mmHg) using multiple logistic regression models. Although a 1-day measurement of the morning uNa/K ratio was positively associated with home hypertension, multiple measurements of the morning uNa/K ratio were strongly related to home hypertension. The average morning uNa/K ratio was relatively stable after 3 days (adjusted odds ratio of home hypertension per unit increase in the uNa/K ratio for more than 3 days: 1.19-1.23). In conclusion, there was no threshold for the uNa/K ratio, and the morning uNa/K ratio was linearly associated with home hypertension. The Na/K ratio 2.0 calculated from the Dietary Reference Intakes for Japanese might be a good indication. Regarding the stability of the association between the morning uNa/K ratio and BP, more than 3 days of measurements is desirable.

Investigation of the urinary sodium-to-potassium ratio target level based on the recommended dietary intake goals for the Japanese population: The INTERMAP Japan

Growing epidemiological evidence has shown an association of the urinary sodium (Na) to potassium (K) ratio (Na/K ratio) with blood pressure and cardiovascular diseases. However, no clear cutoff level has been defined. We investigated the cutoff level of the urinary Na/K ratio under different dietary guidelines for Japanese individuals, especially that endorsed by the 2020 revised Japanese Dietary Reference Intakes (DRIs). A population of 1145 Japanese men and women aged 40 to 59 years from the INTERMAP study was examined. Using high-quality standardized data, the averages of two 24 h urinary collections and four 24 h dietary recalls were used to calculate the 24 h urinary and dietary Na/K ratios, respectively. Associations between the urinary and dietary Na/K ratios were tested by sex- and age-adjusted partial correlation. The optimal urinary Na/K ratio cutoff level was determined by receiver operating characteristic (ROC) curves and sex-specific cross tables for recommended dietary K and salt. Overall, the average molar ratio of 24 h urinary Na/K was 4.3. We found moderate correlations (P < 0.001) of the 24 h urinary Na/K ratio with 24 h urinary Na and K excretion (r = 0.52, r = -0.49, respectively) and the dietary Na/K ratio (r = 0.53). ROC curves showed that a 24 h urinary Na/K ratio of approximately 2 predicted Na and K intake that meets the dietary goals of the Japanese DRIs. The range of urinary Na/K ratios meeting the dietary goals of the Japanese DRIs for both Na and K was 1.6‒2.2 for men and 1.7‒1.9 for women. Accomplishing a urinary Na/K ratio of 2 would be desirable to achieve the DRIs dietary goals for both Na and K simultaneously in middle-aged Japanese men and women accustomed to Japanese dietary habits. This observational study is registered at www.clinicaltrials.gov as NCT00005271.

Validation of Self-Monitoring Devices Supporting Sodium Intake Reduction: An Experimental Feeding Study Using Standardized Low-Salt and High-Salt Meals among Healthy Japanese Volunteers

INTRODUCTION

Although several approaches for approximating daily Na intake and the Na/K ratio using casual urine are available, the most useful method remains unclear during daily practice and at home.

METHODS

Twenty-seven participants measured their casual urinary Na/K ratio repeatedly using a Na/K ratio monitor and also measured overnight urine once daily using a monitoring device which delivers on-site feedback to estimate their salt intake under unrestricted, low-salt (LS) (6 g/day), and high-salt (HS) (12 g/day) diets.

RESULTS

The monitoring method utilizing overnight urine to estimate daily Na remained insensitive, resulting in significant overestimation during the LS diet and underestimation during the HS diet periods; estimated salt intake during the LS and HS diet periods plateaued at 7-8 g/day and 9-10 g/day within 3 day; mean estimated salt intake was 11.3 g/day, 7.9 g/day, and 9.8 g/day on the last day of the unrestricted, LS, and HS diets; the coefficient of variation (CV) of the estimated Na intake was 0.23 and 0.17 in the latter half of the low- and high-salt diet periods, respectively. The mean urinary Na/K molar ratio was 5.6, 2.5, and 5.3 on the last day of the unrestricted, LS, and HS diets; the CV of the daily mean Na/K ratio was 0.41 and 0.36 in the latter half of the LS and HS diet periods, respectively. The urinary Na/K ratio during the LS and HS diet periods plateaued within 2 days. The monitoring method based on the daily mean of the casual urinary Na/K ratio reflected the actual change in Na intake, and the estimated value tracked the actual changes in salt intake with smaller difference than the overnight urine estimates when using the estimation coefficient set at 2; estimated salt intake during the LS and HS diet periods plateaued at 5-6 g/day and 10-12 g/day within 2-3 day; mean estimated salt intake was 11.0 g/day, 5.7 g/day, and 10.7 g/day on the last day of the unrestricted, LS, and HS diets, respectively.

DISCUSSION/CONCLUSION

Estimates of daily Na intake derived from overnight urine may remain insensitive during dietary interventions. The urinary Na/K ratio reflects the actual change in Na intake during dietary modification and may serve as a practical marker, particularly during short-term interventions. Conversion from the urinary Na/K ratio to estimated salt intake may be useful, if the coefficient was set appropriate by further investigations.

Impacts of the urinary sodium-to-potassium ratio, sleep efficiency, and conventional risk factors on home hypertension in a general Japanese population

Recently, a high urinary sodium-to-potassium (Na/K) ratio and reduced sleep efficiency, in addition to conventional risk factors (obesity and excess alcohol intake), have been identified as risk factors for hypertension. We estimated the population attributable fraction (PAF) for home hypertension due to these risk factors in a general Japanese population. We conducted a cross-sectional study including 1384 participants (393 men and 991 women) to estimate the odds ratio (OR) and 95% confidence interval (CI) for the presence of any of the conventional risk factors using multivariable logistic regression analyses. The models were adjusted for sex, age, smoking status, and log-transformed average daily steps. We also estimated the OR and 95% CI for the presence of any of the overall risk factors. Furthermore, we calculated the PAF due to these risk factors. The results showed that the prevalence of home hypertension was 39.0% (540/1384). The presence of any of the conventional risk factors, as well as any of the overall risk factors, was significantly associated with an increased prevalence of hypertension (OR 2.80, 95% CI 2.15-3.65; OR 2.50, 95% CI 1.93-3.22, respectively). The PAF for hypertension due to the presence of any of the conventional risk factors and the PAF due to the presence of any of the overall risk factors were 30.2% and 39.0%, respectively. In conclusion, the impact of the overall risk factors, including the urinary Na/K ratio and sleep efficiency, on home hypertension was higher than that of conventional risk factors alone. The management of the urinary Na/K ratio and sleep efficiency as well as conventional risk factors might be important in the management of blood pressure.

Sodium/potassium ratio change was associated with blood pressure change: possibility of population approach for sodium/potassium ratio reduction in health checkup

Recently, the sodium (Na)/potassium (K) ratio was reported to be associated with blood pressure (BP). A Na/K ratio self-monitoring device using spot urine was established recently. Here, we assessed whether the urinary Na/K ratio change measured using the Na/K device was associated with BP change in a health checkup setting. We targeted 12,890 participants who attended the health checkup in Tome City, Miyagi between 2017 and 2018. Tome City introduced urinary Na/K ratio measurements during health checkups since 2017. For each year, we compared the baseline characteristics according to the urinary Na/K ratio and BP level. We assessed the relationship between change in urinary Na/K ratio and BP change using multiple regression analyses adjusted for age, sex, and change in body mass index (BMI) and alcohol intake. The average urinary Na/K ratio was significantly lower in 2018 than in 2017 (5.4 ± 3.0 to 4.9 ± 2.2, P < 0.01). The systolic BP of the participants in 2018 (130.9 ± 17.4 mmHg) was lower than that in 2017 (132.1 ± 17.9 mmHg). Moreover, the change in systolic BP and diastolic BP was positively associated with the change in urinary Na/K ratio. In conclusion, the association of the change in urinary Na/K ratio with hypertension and changes in systolic and diastolic BP can be explained by a change in alcohol intake, BMI, and urinary Na/K ratio. Therefore, measuring the urinary Na/K ratio in community settings is a potential population approach for counteracting hypertension.

Associations between metabolic syndrome and urinary Na-to-K ratio and glomerular filtration rate in middle-aged adults regardless of Na and K intakes

BACKGROUND

Intake of Na-to-K ratio (I-Na/K), urinary Na-to-K ratio (U-Na/K), and estimated glomerular filtration rate (GFR) have been reported to be risk factors of metabolic syndrome (MetS), but results are inconsistent. We examined the hypothesis that U-Na/K, GFR, and a preference for salty foods are associated with MetS risk and the hypothesis in 8540 adults aged over 40 years without chronic kidney disease.

METHODS

Participants were categorized using a U-Na/K of < 2.1 (low-U-Na/k) and a GFR of < 60 mL/min (low-GFR). A GFR of 60-90 mL/min was considered as a normal level, since it is a normal or marginal disease state. Correlations and associations were determined using Pearson's correlation coefficients and logistic regression analysis after adjusting for covariates related to MetS.

RESULTS

U-Na/K, but not I-Na/K, was positively correlated with blood pressure (r² = 0.20, P < 0.0001). The GFR was negatively correlated with age, gender, HOMA-B, and MetS (r² = - 0.14 to - 0.595, P < 0.0001), and positively correlated with education, current smoking, and alcohol intake (r² = 0.21 to 0.40, P < 0.0001). MetS risk had a positive association with the following combinations with low-U-Na/K + low-GFR, high-U-Na/K + high-GFR, and high-U-Na/K +low-GFR by 1.830-, 3.182-, and 3.696-fold, respectively, as compared with low-U-Na/K + high-GFR. Risks of the MetS components (abdominal obesity, hypertriglyceridemia, hypo-HDL-cholesterolemia, hypertension, and hyperglycemia) were similarly associated with U-Na/K and GFR, though hypertension had the strongest association. Hypertension risk had positive associations with low-U-Na/K + low-GFR, high-U-Na/K + high-GFR, and high-U-Na/K + low-GFR by 1.526-, 14.06-, and 7.079-fold, respectively, as compared with low-U-Na/K + high-GFR.

CONCLUSION

MetS risk was found to be associated with U-Na/K and GFR regardless of I-Na/K. Women need to maintain a high GFR to reduce the MetS risk, especially the risk of hypertension.