Table 1. Baseline characteristics of patients by blood glucose-lowering therapy including variables relevant to magnesium homoeostasis.
Data are percentages, mean±SD, geometric mean (SD range) or median [inter-quartile range].
a<0.05 vs diet alone; b<0.05 vs metformin alone; c<0.05 vs sulfonylurea alone, unadjusted for multiple comparisons.
| Diet | Metformin only | Sulfonylurea only | Metformin+Sulfonylurea | P-value | |
| Number | 350 | 148 | 258 | 184 | |
| Age (years) | 62.7±11.7 | 60.5±12.2 | 65.9±10.9 a,b, | 63.4±11.4 b,c | <0.001 |
| Sex (% male) | 48.6 | 43.9 | 53.9 | 47.3 | 0.24 |
| Diabetes duration (years) | 1.0 [0.3–3.0] | 3.0 [0.8–5.0]a | 4.0 [1.3–7.0]a,b | 8.0 [5.0–12.0]a,b,c | <0.001 |
| Body mass index (kg/m2): | 29.2±5.7 | 31.2±5.2a | 28.7±5.3b | 29.9±5.0 b,c | <0.001 |
| Waist circumference (cm): | |||||
| Men | 100.7±11.1 | 107.9±10.4a | 101.6±11.9b | 104.8±11.9a,c | <0.001 |
| Women | 96.2±14.0 | 98.2±11.5 | 94.6±12.7 | 98.5±11.9 | 0.09 |
| Fasting serum glucose (mmol/L) | 7.2 [6.2–8.6] | 8.7 [7.1–10.2]a | 8.7 [7.4–11.1]a | 9.9 [8.0–11.9]a,b,c | <0.001 |
| HbA1c (%) | 6.5 [5.9–7.4] | 7.6 [6.7–8.7]a | 7.9 [6.6–8.9]a | 8.3 [7.1–9.9]a,b,c | <0.001 |
| Serum magnesium (mmol/L) | 0.85±0.16 | 0.81±0.15a | 0.83±0.14 | 0.74±0.17a,b,c | <0.001 |
| Hypomagnesemia (%) | 11.1 | 17.6 | 14.7 | 41.3 a,b,c | <0.001 |
| Urinary magnesium (mmol/L) | 1.80 (1.01–3.20) | 1.46 (0.84–2.54)a | 1.63 (0.89–2.97)a | 1.31 (0.73–2.37) a,c | <0.001 |
| Fractional excretion urinary magnesium (%) | 2.2 (1.1–4.4) | 1.8 (0.9–3.6)a | 2.1 (1.1–4.0)b | 1.9 (0.9–4.0)a | 0.006 |
| Renal causes (>4.0%) (%) | 15.7 | 10.4 | 14.1 | 12.5 | 0.13 |
| Serum creatinine (mmol/L) | 95±75 | 86±30 | 93±57 | 88±55 | 0.38 |
| Alcohol consumption (standard drinks/day) | 0.0 [0.0–0.8] | 0.0 [0.0–0.3] | 0.0 [0.0–0.5] | 0.0 [0.0–0.3] | 0.64 |
| Diuretic therapy (%) | 18.3 | 22.3 | 26.4 | 17.9 | 0.07 |
| Digoxin therapy (%) | 6.9 | 7.4 | 7.4 | 3.3 | 0.24 |
| Proton pump inhibitor therapy (%) | 0.6 | 1.4 | 0.4 | 1.1 | 0.58 |
| Magnesium supplementation (n = 2)(%) | 0.4 | 0 | 0 | 0.7 | 0.80 |
| Gastrointestinal problems (%) | 2.9 | 2.0 | 1.6 | 3.3 | 0.64 |
Data are percentages, mean ± SD, geometric mean (SD range) or median [inter-quartile range].
a
P<0.05 vs diet alone; b P<0.05 vs metformin alone; c P<0.05 vs sulfonylurea alone, unadjusted for multiple comparisons.