Table 4 Cox proportional hazards analysis of association of obesity categories and risk of hypertension by gender and age groups.

From: Body mass index and waist circumference combined predicts obesity-related hypertension better than either alone in a rural Chinese population

Variables

Age 18–39 years

Age 40–59 years

Age ≥60 years

HR (95% CI)a

HR (95% CI)b

HR (95% CI)a

HR (95% CI)b

HR (95% CI)a

HR (95% CI)b

Men

 BMI (kg/m2) levels

  Normal weight

1.00

1.00

1.00

1.00

1.00

1.00

  Overweight

2.13 (1.41–3.22)

1.85 (1.20–2.86)

1.92 (1.54–2.38)

2.15 (1.70–2.71)

1.15 (0.87–1.51)

1.19 (0.85–1.68)

  General obesity

4.15 (2.51–6.84)

2.93 (1.68–5.11)

2.13 (1.52–2.99)

2.34 (1.61–3.40)

1.31 (0.64–2.66)

1.24 (0.54–2.83)

 WC (cm) levels

  Normal WC

1.00

1.00

1.00

1.00

1.00

1.00

  Central obesity

2.61 (1.78–3.84)

1.87 (1.23–2.86)

1.85 (1.49–2.29)

1.83 (1.45–2.31)

1.05 (0.75–1.48)

1.12 (0.75–1.69)

 BMI (kg/m2) /WC (cm) levels*

  BNWN

1.00

1.00

1.00

1.00

1.00

1.00

  BOWN

1.86 (1.14–3.04)

1.78 (1.06–2.99)

1.74 (1.34–2.27)

2.02 (1.53–2.68)

1.27 (0.91–1.78)

1.30 (0.86–1.97)

  BNWO

0

0

1.79 (0.73–4.36)

1.12 (0.35–3.53)

2.15 (0.53–8.72)

3.61 (0.84–15.57)

  BOWO

3.20 (2.11–4.86)

2.29 (1.45–3.62)

2.20 (1.73–2.79)

2.32 (1.79–3.00)

1.07 (0.75–1.53)

1.13 (0.73–1.73)

Women

 BMI (kg/m2) levels

  Normal weight

1.00

1.00

1.00

1.00

1.00

1.00

  Overweight

2.25 (1.58–3.19)

1.95 (1.37–2.79)

1.59 (1.33–1.90)

1.57 (1.30–1.89)

1.14 (0.88–1.48)

1.24 (0.90–1.70)

  General obesity

4.58 (3.05–6.89)

3.13 (2.02–4.84)

2.08 (1.65–2.62)

2.13 (1.67–2.72)

1.05 (0.70–1.59)

0.99 (0.62–1.59)

 WC (cm) levels

  Normal WC

1.00

1.00

1.00

1.00

1.00

1.00

  Central obesity

2.89 (2.10–3.98)

2.45 (1.77–3.39)

1.53 (1.30–1.81)

1.50 (1.26–1.79)

0.97 (0.76–1.24)

0.97 (0.72–1.31)

 BMI (kg/m2) /WC (cm) levels*

  BNWN

1.00

1.00

1.00

1.00

1.00

1.00

  BOWN

1.90 (1.03–3.52)

1.53 (0.82–2.84)

1.57 (1.17–2.10)

1.57 (1.14–2.16)

1.10 (0.60–2.00)

1.32 (0.67–2.58)

  BNWO

2.18 (1.20–3.96)

1.96 (1.07–3.58)

1.20 (0.87–1.65)

1.14 (0.81–1.60)

0.84 (0.60–1.20)

0.85 (0.55–1.31)

  BOWO

3.49 (2.45–4.98)

2.81 (1.96–4.03)

1.81 (1.50–2.18)

1.77 (1.45–2.16)

1.05 (0.80–1.38)

1.08 (0.78–1.51)

  1. Data are expressed as hazard ratios with 95% confidence interval.
  2. BMI, body mass index; WC, waist circumference; HR, hazard ratio; CI, confidence interval.
  3. *Based on the diagnose criteria: BNWN, 18.5≤BMI<24, WC<90 for men and WC<80 for women; BOWN, BMI≥24, WC<90 for men and WC<80 for women; BNWO, 18.5≤BMI<24, WC≥90 for men and WC≥80 for women; BOWO, BMI≥24, WC≥90 for men and WC≥80 for women.
  4. aUnadjusted model.
  5. bAdjusted for age, education level, smoking, drinking, physical activity and family history of hypertension.