Table 2

Longitudinal association between BMI and WC, and pre-frailty/frailty: the Tromsø study 1994–2016

Frailty status
Robust
(% (n))
Pre-frail/frail
(% (n))
Model 1
OR (95% CI)
Model 2
OR (95% CI)
BMI, kg/m2 70.5 (3179)29.5 (1330)
 Underweight0.3 (11)0.7 (9)2.15 (0.88 to 5.29)1.32 (0.49 to 3.54)
 Normal47.6 (1513)39.3 (522)Ref.Ref.
 Overweight43.7 (1388)43.0 (572)1.18 (1.02 to 1.36)1.19 (1.02 to 1.39)
 Obesity8.4 (267)17.0 (227)2.42 (1.98 to 2.98)2.41 (1.93 to 3.02)
WC, cmn=952n=582
 Normal51.5 (490)37.3 (217)Ref.Ref.
 Moderately high31.1 (296)35.0 (204)1.54 (1.21 to 1.96)*1.57 (1.21 to 2.03)*
 High17.4 (166)27.7 (161)2.16 (1.65 to 2.83)*2.14 (1.59 to 2.87)*
  • Model 1: adjusted for age and sex (*excluding sex) at baseline. Model 2: adjusted for age, sex, educational level, marital/cohabitation status, smoking status, alcohol intake, social support, self-perceived health and physical activity level (*excluding sex) at baseline.

  • BMI categories: Underweight: <18.5 kg/m2. Normal: 18.5–24.9 kg/m2. Overweight: 25.0–29.9 kg/m2. Obesity: ≥30 kg/m2.

  • WC categories: Normal: men ≤94 cm; women ≤80 cm. Moderately high: men 95–102 cm; women 81–88 cm. High: men >102 cm; women >88 cm.

  • BMI, body mass index; WC, waist circumference.