Table 3. Estimated odds ratios (ORs) for S. aureus nasal colonization by body mass index (BMI) in age tertiles of women and men.
| Women (n = 2,169) a | Men (n = 1,709) a | ||||||
| BMI | Total | Colonized | Total | Colonized | |||
| (kg/m2) | na | n a(%) | ORb (95% CI) | na | n a(%) | ORb (95% CI) | |
| 30–43 years | |||||||
| <22.5 | 169 | 35 (20.7) | ref | 59 | 30 (55.9) | ref | |
| 22.5–<25.0 | 169 | 38 (22.5) | 1.02 (0.59–1.76) | 130 | 50 (38.5) | 0.58 (0.31–1.09) | |
| 25.0–<27.5 | 130 | 33 (25.4) | 1.31 (0.75–2.30) | 152 | 61 (40.1) | 0.68 (0.37–1.25) | |
| 27.5–<30.0 | 84 | 19 (22.6) | 1.04 (0.54–2.03) | 132 | 51 (38.6) | 0.66 (0.35–1.25) | |
| 30.0–<32.5 | 54 | 14 (25.9) | 1.26 (0.59–2.70) | 73 | 27 (37.0) | 0.60 (0.29–1.24) | |
| ≥32.5 | 71 | 26 (36.6) | 2.60 (1.35–4.98) | 36 | 16 (44.4) | 0.85 (0.36–1.97) | |
| Ptrend | 0.01 | 0.75 | |||||
| 44–59 years | |||||||
| <22.5 | 148 | 29 (19.6) | ref | 31 | 11 (35.5) | ref | |
| 22.5–<25.0 | 168 | 45 (26.8) | 1.35 (0.76–2.38) | 101 | 41 (40.6) | 1.06 (0.45–2.51) | |
| 25.0–<27.5 | 149 | 29 (19.5) | 1.11 (0.61–2.01) | 183 | 68 (37.2) | 1.04 (0.46–2.36) | |
| 27.5–<30.0 | 101 | 18 (17.8) | 1.01 (0.51–2.01) | 147 | 53 (36.1) | 0.92 (0.40–2.11) | |
| 30.0–<32.5 | 68 | 18 (26.5) | 1.63 (0.80–3.29) | 63 | 25 (39.7) | 1.21 (0.48–3.04) | |
| ≥32.5 | 57 | 11 (19.3) | 1.06 (0.46–2.44) | 63 | 26 (41.3) | 1.06 (0.42–2.68) | |
| Ptrend | 0.69 | 0.91 | |||||
| 60–87 years | |||||||
| <22.5 | 125 | 27(21.6) | ref | 145 | 32 (22.1) | refc | |
| 22.5–<25.0 | 133 | 30 (22.6) | 1.25 (0.63–2.47) | ||||
| 25.0–<27.5 | 183 | 40 (21.9) | 1.26 (0.67–2.37) | 144 | 38 (26.4) | 1.18 (0.65–2.13) | |
| 27.5–<30.0 | 163 | 39 (23.9) | 1.14 (0.59–2.20) | 131 | 49 (37.4) | 1.90 (1.07–3.37) | |
| 30.0–<32.5 | 101 | 21 (20.8) | 1.00 (0.46–2.14) | 78 | 24 (30.8) | 1.49 (0.77–2.86) | |
| ≥32.5 | 96 | 26 (27.1) | 1.60 (0.77–3.32) | 41 | 13 (31.7) | 1.34 (0.58–3.12) | |
| Ptrend | 0.50 | 0.14 | |||||
The Tromsø Staph and Skin Study (n = 3,878)a.
n, numbers; CI, confidence intervals.
P for interaction using BMI categories as Ptrend and age tertiles (middle versus lowest), among women: 0.15 and men: 0.66; age tertiles (highest versus lowest), among women: 0.42 and men: 0.11.
a
Numbers may vary due to missing information.
b
Multivariable logistic regression model including: current smoking (yes/no), diabetes mellitus (yes/no), education level (< or ≥ college/university degree), and household income (< or ≥ level of the lowest income quintile).
c
Among men 60–87 years, the BMI categories <22.5 and 22.5–<25.0 kg/m2 were put together due to small numbers.