Table 2.

HRs for the risk of mortality in subgroups

Subgroups	BMI category	HR (95% CI)	P-value for interaction
Sex
Male	Underweight	2.074 (1.272 to 3.383)	0.68
	Overweight	0.873 (0.756 to 1.008)
	Obese	0.890 (0.730 to 1.084)
Female	Underweight	1.394 (0.917 to 2.119)
	Overweight	0.866 (0.721 to 1.039)
	Obese	0.864 (0.691 to 1.082)
Age
>65	Underweight	1.595 (1.140 to 2.230)	0.38
	Overweight	0.896 (0.794 to 1.011)
	Obese	0.911 (0.771 to 1.076)
≤65	Underweight	1.964 (0.714 to 5.406)
	Overweight	0.687 (0.495 to 0.952)
	Obese	0.709 (0.492 to 1.023)
Diabetes mellitus
Diabetic	Underweight	2.591 (1.051 to 6.385)	0.62
	Overweight	0.937 (0.736 to 1.194)
	Obese	0.877 (0.674 to 1.143)
Non-diabetic	Underweight	1.535 (1.092 to 2.157)
	Overweight	0.851 (0.748 to 0.968)
	Obese	0.898 (0.745 to 1.082)
Smoking
Current smoker	Underweight	1.766 (1.017 to 3.066)	0.67
	Overweight	0.782 (0.611 to 1.001)
	Obese	0.917 (0.674 to 1.249)
Non-smoker	Underweight	1.550 (1.049 to 2.291)
	Overweight	0.893 (0.786 to 1.015)
	Obese	0.871 (0.733 to 1.034)

There were no significant interactions between dichotomous subgroups and BMI categories with respect to 1-year mortality.

BMI, body mass index.