(3) Cardiovascular disease The rates and severity of cardiovascular disease differ between the sexes and these differences have been evaluated in the elderly [71] . As they have not been identified as an at-risk population for severe disease from 2009 H1N1 influenza, sex differences in cardiovascular disease may not be a critical factor. (4) Metabolic disorders Diabetes and morbid obesity have emerged as novel risk factors for severe 2009 H1N1 disease [3] . The lifetime risk of diabetes is higher in women than men, at least in the USA where approximately 55% of all diabetic-related deaths are women which may be a reflection of the fact that women tend to live longer than men [72] . In the USA, gestational diabetes and rates of diabetes in obese adolescent girls have been increasing [73, 74] . Gestational diabetes occurs in up to 14% of all pregnancies [75] . Women, particularly those of lower socioeconomic status, also receive less adequate diabetes care than men of the same socioeconomic status [76] .