Serum Magnesium is Inversely Associated with Body Composition and Metabolic Syndrome

Figures & data

Table 1 Sample Characteristics by Quartiles of Serum Magnesium Among Participants Attending Qatar Biobank Study (N=1000)

	Q1	Q2	Q3	Q4	P value
	N=303	N=260	N=203	N=234
Magnesium (mmol/L)	0.77(0.03)	0.83 (0.01)	0.86 (0.01)	0.91 (0.03)	<0.001
Age	36.1 (10.4)	35.7 (10.9)	36.6 (10.5)	36.2 (10.4)	0.817
Sex					<0.001
Male	121 (39.9%)	137 (52.7%)	98 (48.3%)	137 (58.5%)
Female	182 (60.1%)	123 (47.3%)	105 (51.7%)	97 (41.5%)
Education					0.700
Low	18 (5.9%)	13 (5.0%)	11 (5.4%)	6 (2.6%)
Medium	83 (27.4%)	71 (27.4%)	57 (28.1%)	70 (30.0%)
High	202 (66.7%)	175 (67.6%)	135 (66.5%)	157 (67.4%)
Smoking					0.072
Non	221 (72.9%)	168 (64.6%)	144 (70.9%)	153 (65.4%)
Smoker	42 (13.9%)	47 (18.1%)	36 (17.7%)	53 (22.6%)
Ex-smoker	40 (13.2%)	45 (17.3%)	23 (11.3%)	28 (12.0%)
Leisure time physical activity (MET hours/week)	6.3 (30.0)	6.3 (17.7)	6.0 (20.1)	5.4 (17.1)	0.967
BMI (kg/m^2)	28.6 (5.6)	28.5 (6.2)	27.9 (5.9)	27.5 (5.1)	0.090
BMI categories					0.131
Normal	82 (27.1%)	75 (28.8%)	72 (35.5%)	69 (29.5%)
Overweight	119 (39.3%)	93 (35.8%)	73 (36.0%)	103 (44.0%)
Obese	102 (33.7%)	92 (35.4%)	58 (28.6%)	62 (26.5%)
Cholesterol Total (mmol/l)	4.8 (0.9)	4.9 (0.9)	5.1 (1.0)	5.0 (1.0)	0.007
HDL-Cholesterol(mmol/l)	1.4 (0.4)	1.4 (0.4)	1.4 (0.4)	1.3 (0.3)	0.018
Triglyceride (mmol/l)	1.3 (0.8)	1.4 (1.2)	1.3 (0.8)	1.4 (0.9)	0.213
LDL-Cholesterol (mmol/l)	2.9 (0.8)	2.9 (0.8)	3.1 (0.9)	3.1 (0.9)	0.001
Supplement use	200 (66.0%)	158 (60.8%)	125 (61.6%)	136 (58.1%)	0.292
Vitamin D and calcium use	136 (44.9%)	99 (38.1%)	76 (37.4%)	75 (32.1%)	0.024
Vegetable intake (times/week)	17.9 (14.4)	17.4 (14.9)	15.4 (12.0)	17.3 (13.2)	0.250
Fruit intake (times/week)	7.2 (6.5)	6.6 (6.2)	7.2 (5.8)	6.3 (5.9)	0.310
Dietary pattern 1	0.05 (1.15)	−0.03 (0.93)	−0.03 (0.93)	−0.01 (0.93)	0.711
Dietary pattern 2	0.03 (1.03)	0.01 (1.02)	0.00 (0.96)	−0.05 (0.98)	0.800
Dietary pattern 3	0.06 (1.09)	0.05 (1.01)	−0.01 (1.01)	−0.11 (0.85)	0.220
eGFR (mL/min/1.73m^2)	113.5 (14.3)	111.8 (13.6)	110.7 (14.0)	109.2 (14.0)	0.003
HbA1C (%)	5.7 (1.2)	5.5 (0.8)	5.5 (0.7)	5.5 (0.6)	0.010
Hypertension	39 (12.9%)	21 (8.1%)	21 (10.3%)	21 (9.0%)	0.260
Diabetes	48 (16.4%)	29 (11.5%)	17 (8.9%)	25 (11.2%)	0.072
Metabolic syndrome	61 (20.1%)	33 (12.7%)	27 (13.3%)	31 (13.2%)	0.041
Insulin use	13 (4.3%)	5 (1.9%)	2 (1.0%)	0 (0.0%)	0.003
Diabetes medication other than insulin	30 (9.9%)	12 (4.6%)	8 (3.9%)	8 (3.4%)	0.003
Hypertension medication use	31 (10.2%)	11 (4.2%)	7 (3.4%)	9 (3.8%)	0.001
PHQ-9 score	6.6 (4.8)	6.4 (4.6)	6.0 (4.6)	5.8 (4.4)	0.160
Sleep duration <7 hours	164 (54.5%)	131 (50.4%)	119 (58.9%)	128 (56.9%)	0.280
CRP ≥6 (mg/L)	67 (22.1%)	46 (17.7%)	41 (20.2%)	47 (20.1%)	0.490
Total fat mass (kg)	31.5 (11.2)	30.5 (11.7)	29.6 (11.2)	29.0 (10.3)	0.055
Trunk fat (kg)	16.0 (6.6)	15.7 (6.8)	15.2 (6.6)	15.1 (6.3)	0.420
Gynoid fat mass (kg)	5.4 (1.8)	5.2 (2.0)	5.0 (1.9)	4.8 (1.7)	0.003
Android fat mass (kg)	2.6 (1.3)	2.6 (1.3)	2.5 (1.3)	2.5 (1.2)	0.560

Notes: Data are presented as mean (SD) for continuous measures, and n (%) for categorical measures.

Abbreviations: CRP, c-reactive protein; PHQ-9, Patient Health Questionnaire.

Table 2 Association Between Serum Magnesium and Fat Mass Among Qatari Adults (N=1000)

	Quartiles of Serum Magnesium				p -value for Trend	Serum Magnesium (Continuous, Per SD)
	Q1	Q2	Q3	Q4			p -value
Total fat mass
Unadjusted	0.00	−0.94 (−2.78,0.91)	−1.84 (−3.82,0.14)	−2.52 (−4.41,-0.62)	0.006	−1.33 (−2.02, −0.65)	<0.001
Adjusted *	0.00	−0.34 (−2.14,1.46)	−1.53 (−3.45,0.40)	−1.65 (−3.52,0.22)	0.044	−0.98 (−1.66, −0.30)	0.005
Trunk fat mass
Unadjusted	0.00	−0.27 (−1.37, 0.82)	−0.78 (−1.96, 0.39)	−0.82 (−1.94, 0.31)	0.105	−0.59 (−1.00, −0.18)	0.004
Adjusted *	0.00	−0.21 (−1.26, 0.83)	−0.82 (−1.94, 0.29)	−0.80 (−1.88, 0.29)	0.089	−0.53 (−0.93, −0.14)	0.008
Gynoid fat mass
Unadjusted	0.00	−0.19 (−0.50, 0.13)	−0.39 (−0.73, −0.06)	−0.58 (−0.91, −0.26)	<0.001	−0.26 (−0.37, −0.14)	<0.001
Adjusted *	0.00	−0.03 (−0.34, 0.27)	−0.29 (−0.61, 0.03)	−0.34 (−0.65, −0.03)	0.013	−0.17 (−0.29, −0.06)	0.003
Android fat mass
Unadjusted	0.00	−0.05 (−0.26, 0.16)	−0.14 (−0.36, 0.09)	−0.13 (−0.35, 0.09)	0.171	−0.11 (−0.19, −0.03)	0.007
Adjusted *	0.00	−0.05 (−0.25, 0.15)	−0.15 (−0.37, 0.06)	−0.15 (−0.35, 0.06)	0.106	−0.10 (−0.18, −0.03)	0.008

Notes: Values are regression coefficients (95% CI). Bold fonts represent statistically significant regression coefficients. *Model adjusted for age, gender, education, smoking, physical activity, and dietary patterns.

Table 3 Subgroup Analyses of the Association Between Serum Magnesium and Fat Mass

	Total Fat Mass		Trunk Fat		Gynoid Fat		Android Fat
	β (95% CI)	p*	β (95% CI)	p*	β (95% CI)	p*	β (95% CI)	p*
Gender		0.654		0.468		0.491		0.477
Male	−1.20 (−2.23, −0.17)		−0.71 (−1.34, −0.09)		−0.22 (−0.39, −0.05)		−0.14 (−0.26, −0.02)
Female	−0.81 (−1.70, 0.08)		−0.39 (−0.89, 0.10)		−0.13 (−0.29, 0.02)		−0.08 (−0.17, 0.01)
Diabetes		0.145		0.493		0.031		0.480
No	−1.22 (−1.98, −0.46)		−0.56 (−0.99, −0.12)		−0.24 (−0.37, −0.11)		−0.11 (−0.19, −0.02)
Yes	0.28 (−1.44, 1.99)		−0.12 (−1.22, 0.98)		0.08 (−0.18, 0.34)		−0.03 (−0.23, 0.18)
Hypertension		0.147		0.237		0.205		0.235
No	−0.75 (−1.47, −0.03)		−0.41 (−0.83, 0.00)		−0.14 (−0.26, −0.02)		−0.08 (−0.16, 0.00)
Yes	−2.08 (−4.18, 0.02)		−1.05 (−2.24, 0.15)		−0.36 (−0.69, −0.04)		−0.22 (−0.44, 0.01)
Smoking		0.570		0.848		0.460		0.903
None	−1.19 (−1.99, −0.39)		−0.60 (−1.06, −0.14)		−0.22 (−0.35, −0.08)		−0.11 (−0.20, −0.03)
Smoker	−0.87 (−2.54, 0.79)		−0.48 (−1.48, 0.52)		−0.12 (−0.39, 0.15)		−0.10 (−0.29, 0.10)
Ex-smoker	−0.59 (−2.80, 1.62)		−0.47 (−1.82, 0.88)		−0.10 (−0.46, 0.25)		−0.10 (−0.37, 0.16)
Sleep duration		0.108		0.101		0.111		0.157
<7 hrs	−0.47 (−1.34, 0.39)		−0.22 (−0.73, 0.29)		−0.09 (−0.24, 0.05)		−0.05 (−0.15, 0.05)
≥7 hrs	−1.60 (−2.71, −0.49)		−0.89 (−1.52, −0.26)		−0.28 (−0.47, −0.09)		−0.16 (−0.28, −0.04)
PHQ-9 score		0.931		0.547		0.415		0.518
<10	−0.96 (−1.66, −0.26)		−0.48 (−0.88, −0.08)		−0.19 (−0.31, −0.08)		−0.09 (−0.17, −0.01)
≥10	−0.64 (−2.71, 1.42)		−0.51 (−1.76, 0.74)		−0.04 (−0.39, 0.32)		−0.11 (−0.34, 0.13)
CRP		0.804		0.960		0.867		0.682
<6 mg/L	−1.07 (−1.77, −0.37)		−0.57 (−0.98, −0.17)		−0.20 (−0.32, −0.08)		−0.12 (−0.20, −0.04)
≥6 mg/L	−1.29 (−3.00, 0.42)		−0.64 (−1.64, 0.36)		−0.18 (−0.46, 0.11)		−0.09 (−0.28, 0.09)
Supplement use		0.921		0.711		0.741		0.688
No	−0.99 (−2.14, 0.15)		−0.46 (−1.13, 0.22)		−0.20 (−0.40, −0.01)		−0.09 (−0.22, 0.04)
Yes	−0.83 (−1.68, 0.02)		−0.50 (−1.00, −0.01)		−0.14 (−0.28, 0.01)		−0.10 (−0.19, −0.01)

Notes:*p for interaction. Model adjusted for age, gender, education, smoking, physical activity, and dietary patterns. Stratification variables were not adjusted in corresponding models. Values represent regression coefficients (95% CI) for per SD increase of serum magnesium. Bold fonts represent statistically significant regression coefficients (95% CI).

Table 4 Association Between Serum Magnesium and Metabolic Syndrome Among Qatari Adults (N=1000)

	Quartiles of Serum Magnesium					Serum Magnesium (Continuous, Per SD)
	Q1	Q2	Q3	Q4	P for Trend		P value
Metabolic syndrome
Unadjusted	1.00	0.58 (0.36–0.91)	0.61 (0.37–1.00)	0.61 (0.38–0.97)	0.032	0.70 (0.59–0.84)	<0.001
Adjusted	1.00	0.52 (0.30–0.89)	0.53 (0.30–0.94)	0.55 (0.31–0.96)	0.030	0.70 (0.57–0.85)	<0.001
Elevated blood pressure
Unadjusted	1.00	0.69 (0.44–1.08)	0.86 (0.54–1.37)	0.83 (0.53–1.29)	0.529	0.93 (0.79–1.10)	0.379
Adjusted	1.00	0.61 (0.36–1.01)	0.78 (0.46–1.31)	0.70 (0.42–1.18)	0.267	0.93 (0.77–1.12)	0.433
Reduced HDL
Unadjusted	1.00	0.66 (0.45–0.95)	0.84 (0.57–1.23)	0.91 (0.63–1.32)	0.791	0.92 (0.81–1.06)	0.261
Adjusted	1.00	0.67 (0.46–0.98)	0.83 (0.56–1.23)	0.90 (0.61–1.32)	0.723	0.92 (0.80–1.06)	0.265
Elevated TG
Unadjusted	1.00	0.76 (0.53–1.10)	0.63 (0.42–0.95)	0.87 (0.60–1.26)	0.268	0.84 (0.73–0.96)	0.013
Adjusted	1.00	0.68 (0.45–1.02)	0.53 (0.34–0.83)	0.73 (0.48–1.11)	0.067	0.79 (0.68–0.93)	0.004
Elevated glucose
Unadjusted	1.00	0.68 (0.44–1.06)	0.51 (0.30–0.85)	0.70 (0.44–1.10)	0.051	0.73 (0.61–0.87)	<0.001
Adjusted	1.00	0.67 (0.41–1.10)	0.48 (0.27–0.84)	0.68 (0.41–1.14)	0.055	0.74 (0.61–0.89)	0.002
Central obesity
Unadjusted	1.00	0.97 (0.66–1.42)	0.92 (0.60–1.39)	0.80 (0.53–1.21)	0.287	0.86 (0.74–0.99)	0.042
Adjusted	1.00	1.06 (0.70–1.61)	0.94 (0.60–1.48)	0.92 (0.59–1.43)	0.630	0.92 (0.79–1.08)	0.293

Notes: Model adjusted for age, gender, education, smoking, physical activity, and dietary patterns. Values represent odds ratio (95% CI). Bold fonts represent statistically significant odds ratios (95% CI).