Association Between Sodium Density and Grip Strength Among Older Korean Adults: A Nationwide Cross-Sectional Study

Figures & data

Table 1 Characteristics of the Subjects

Variable	Men		P-value	Women		P-value
	Dynapenia^a	Normal		Dynapenia^a	Normal
	(n=155)	(n=1289)		(n=422)	(n=1116)
Age			<0.001			<0.001
65–69	10.1% (1.5%)	40.8% (1.0%)		15.3% (1.3%)	37.6% (1.1%)
70–74	18.0% (2.0%)	29.4% (0.9%)		19.9% (1.2%)	34.1% (1.1%)
75–79	28.8% (2.5%)	20.4% (0.7%)		30.8% (1.5%)	20.2% (0.7%)
80 ≤	43.0% (2.8%)	9.4% (0.6%)		33.9% (1.6%)	8.0% (0.5%)
Height (cm)	162.01(0.29)	165.67(0.11)	<0.001	148.78(0.19)	152.87(0.10)	<0.001
Weight (kg)	60.21(0.44)	65.29(0.19)	<0.001	52.65(0.31)	57.49(0.18)	<0.001
Body mass index (kg/m^Citation2)	22.94(0.18)	23.75(0.06)	<0.001	23.76(0.13)	24.57(0.06)	<0.001
Waist circumference (cm)	84.81(0.41)	86.53(0.18)	<0.001	83.25(0.36)	84.51(0.21)	0.003
Education attainment			<0.001			<0.001
Less than middle school	54.7% (3.2%)	31.2% (1.0%)		81.2% (1.8%)	60.4% (1.2%)
Middle-High school and higher	45.3% (3.2%)	68.8% (1.0%)		18.8% (1.8%)	39.6% (1.2%)
Marital status			<0.001			<0.001
Single/widowed/divorced	20.9% (2.7%)	10.7% (0.6%)		59.8% (1.8%)	47.1% (0.9%)
Married	79.1% (2.7%)	89.3% (0.6%)		40.2% (1.8%)	52.9% (0.9%)
Smoking			0.554			<0.001
Never smoker	26.2% (2.9%)	23.1% (0.9%)		90.9% (1.1%)	96.3% (0.4%)
Ex-smoker	56.2% (3.1%)	57.4% (1.0%)		4.8% (0.5%)	2.2% (0.3%)
Current smoker	17.6% (2.9%)	19.5% (0.8%)		4.3% (1.0%)	1.4% (0.2%)
Alcohol			<0.001			<0.001
No	47.1% (3.6%)	29.9% (1.0%)		70.2% (1.8%)	57.7% (1.2%)
Mild to moderate drinking	50.1% (3.6%)	61.8% (1.0%)		29.7% (1.8%)	41.8% (1.2%)
High risk drinking	2.8% (1.0%)	8.3% (0.5%)		0.1% (0.0%)	0.5% (0.1%)
Physical exercise
Resistance exercise (>2/week)	10.6% (1.6%)	31.9% (1.0%)	<0.001	3.4% (0.9%)	10.8% (0.8%)	<0.001
Aerobic exercise	29.8% (2.7%)	49.4% (1.0%)	<0.001	21.7% (1.9%)	34.5% (1.1%)	<0.001
Walking physical activity	25.8% (3.2%)	46.3% (1.1%)	<0.001	32.4% (2.1%)	40.8% (1.3%)	0.001
Energy (kcal/day)^b	1703.39(36.22)	2010.05(14.32)	<0.001	1308.60(17.03)	1528.00(11.52)	<0.001
Sodium intake (mg/day)^b	3047.40(113.39)	3899.00(51.15)	<0.001	2393.27(67.69)	2677.78(33.50)	<0.001
Sodium intake (mg/day)^c
Q1	39.5% (2.7%)	23.6% (0.8%)	<0.001	35.3% (1.7%)	21.5% (0.9%)	<0.001
Q2	19.6% (2.1%)	25.0% (0.9%)		23.7% (2.0%)	27.8% (0.9%)
Q3	24.9% (1.9%)	24.7% (0.8%)		20.4% (1.3%)	25.4% (0.8%)
Q4	16.1% (2.4%)	26.8% (0.8%)		20.5% (1.4%)	25.3% (0.9%)
Sodium density (mg/1000kcal)^b	1869.69(47.74)	1968.71(21.62)	0.006	1848.70(42.50)	1763.93(19.76)	0.426
Sodium density (mg/1000kcal)^d			0.009			0.013
Q1	28.1% (2.4%)	19.9% (0.7%)		30.8% (1.5%)	29.4% (1.0%)
Q2	21.4% (2.4%)	26.2% (0.9%)		20.7% (1.4%)	24.9% (0.9%)
Q3	23.3% (2.2%)	25.8% (0.9%)		23.1% (1.4%)	25.0% (0.9%)
Q4	27.2% (2.7%)	28.1% (0.8%)		25.3% (1.7%)	20.7% (0.9%)
Potassium (mg/day)^b	2456.38(73.59)	3146.35(32.28)	<0.001	1950.39(39.47)	2633.25(26.01)	<0.001
Potassium density (mg/1000kcal)^b	1444.94(36.13)	1582.14(11.27)	<0.001	1512.19(23.74)	1742.10(15.87)	<0.001
Sodium to Potassium ratio^b	1.51(0.05)	1.33(0.02)	0.384	1.34 (0.03)	1.10 (0.16)	<0.001
Sodium to Potassium ratio^e			0.001			<0.001
Q1	15.6% (2.1%)	15.4% (0.8%)		22.2% (1.5%)	26.9% (1.1%)
Q2	17.9% (1.8%)	23.9% (0.8%)		21.0% (1.3%)	26.7% (0.9%)
Q3	39.2% (3.0%)	28.1% (0.9%)		23.5% (1.6%)	25.3% (0.8%)
Q4	27.3% (2.5%)	32.6% (0.9%)		33.3% (1.6%)	21.0% (0.8%)
Protein (g/day)^b	51.69(1.37)	66.09(0.59)	<0.001	39.75(0.68)	49.06(0.47)	<0.001
Carbohydrate (g/day)^b	305.17(6.86)	336.46(2.22)	<0.001	243.46(3.01)	275.81(2.21)	<0.001
Fat (g/day)^b	21.58(0.74)	32.41(0.47)	<0.001	17.29(0.48)	23.75(0.37)	<0.001
Vitamin C (mg/day)^b	87.28(6.79)	111.32(2.24)	<0.001	65.53(2.69)	116.5(2.51)	<0.001
Handgrip strength (kg)^b	22.08(0.25)	35.93(0.11)	<0.001	14.83(0.08)	23.13(0.06)	<0.001
> 3kg of weight loss within past 1 year	18.8% (1.8%)	13.3% (0.7%)	0.003	14.7% (1.3%)	12.1% (0.6%)	0.040
Charlson Comorbidity Index			0.086			0.180
0	70.4% (2.8%)	68.2% (0.9%)		64.0% (2.0%)	67.0% (1.0%)
1–2	24.8% (2.7%)	28.7% (0.9%)		35.1% (2.0%)	32.2% (1.0%)
≥3	4.7% (0.3%)	3.1% (0.3%)		0.8% (0.0%)	0.8% (0.0%)

Notes: Data are means ± standard error or an estimated percentage (standard error), as appropriate. p-values are those for the t-test for means and chi-square test or Fisher’s exact test for proportions. ^aAccording to the recommendation of Asian Working Group for Sarcopenia, we defined dynapenia as handgrip strength <26 kg for men and <18 kg for women. ^bValues are the estimated means, but log-transformed values were used for comparisons. ^cMen Q1 (−2152.53), Q2 (2152.53–3217.42), Q3 (3217.42–4700.53), Q4 (4700.53-), Women, Q1 (−1420.52), Q2 (1420.52–2305.01), Q3 (2305.01–3412.79), Q4 (3412.79-) ^dMen, Q1 (−1253.18), Q2 (1253.18–1741.89), Q3 (1741.89–2401.55), Q4 (2401.55-), Women, Q1 (−1113.99), Q2 (1113.99–1610.93), Q3 (1610.93–2260.40), Q4 (2260.40-) ^eMen Q1 (−0.8452), Q2 (0.8452–1.1723), Q3 (1.1723–1.6081), Q4 (1.6081-), Women, Q1 (−0.7088), Q2 (0.7088–1.031), Q3 (1.031–1.466), Q4 (1.466-).

Table 2 The Association of Sodium Density with Dynapenia

	Crude		Model1		Model2		Model3
	OR	(95% CI)	OR	(95% CI)	OR	(95% CI)	OR	(95% CI)
Total study population
Sodium density (mg/1000 kcal)
Q1 (−1177.94)	1.53	(1.25–1.86)	1.25	(1.00–1.55)	1.16	(0.90–1.51)	1.03	(0.79–1.35)
Q2 (1177.94–1675.48)	1		1		1		1
Q3 (1675.48–2356.22)	1.12	(0.92–1.36)	1.13	(0.93–1.37)	1.13	(0.90–1.42)	1.12	(0.89–1.41)
Q4 (2356.22-)	1.28	(1.04–1.58)	1.45	(1.16–1.81)	1.40	(1.08–1.82)	1.39	(1.07–1.80)
Men
Sodium density (mg/1000 kcal)
Q1 (−1253.18)	1.61	(1.13–2.29)	1.55	(1.07–2.25)	1.16	(0.71–1.90)	1.08	(0.68–1.72)
Q2 (1253.18–1741.89)	1		1		1		1
Q3 (1741.89–2401.55)	1.29	(0.92–1.79)	1.25	(0.87–1.78)	1.28	(0.85–1.94)	0.99	(0.68–1.43)
Q4 (2401.55-)	1.15	(0.79–1.66)	1.12	(0.77–1.64)	1.06	(0.68–1.66)	1.15	(0.71–1.86)
Women
Sodium density (mg/1000 kcal)
Q1 (−1113.99)	1.47	(1.16–1.87)	1.40	(1.08–1.83)	1.63	(1.18–2.25)	1.01	(0.74–1.38)
Q2 (1113.99–1610.93)	1		1		1		1
Q3 (1610.93–2260.40)	1.04	(0.82–1.33)	1.10	(0.86–1.40)	1.24	(0.93–1.65)	1.18	(0.89–1.58)
Q4 (2260.40-)	1.62	(1.26–2.09)	1.95	(1.47–2.57)	1.98	(1.43–2.74)	1.51	(1.10–2.07)

Notes: Model1: age, BMI. Model2: age, BMI, smoking, alcohol drinking, education, marital status. Model3: age, BMI, smoking, alcohol drinking, education, marital status, Charlson comorbidity index, > 3kg of weight loss within past 1 year, protein intake, total energy intake, potassium intake, resistance exercise, aerobic exercise.

Abbreviations: CI, confidence interval; OR, odds ratio.

Figure 1 Association of sodium density with dynapenia among men.

Figure 2 Association of sodium density with dynapenia among women.

Cruz-Jentoft AJ, Baeyens JP, Bauer JM, et al. Sarcopenia: european consensus on definition and diagnosis: report of the European Working Group on Sarcopenia in Older People. Age Ageing. 2010;39(4):412–423. doi:10.1093/ageing/afq03420392703

 PubMed Web of Science ®Google Scholar

Data Availability

The KNHANES data can be downloaded from the web site, https://knhanes.cdc.go.kr/knhanes/main.do.