Any role of frailty?
Frailty has not been formally assessed as a risk factor for COVID-19 infection in people with diabetes. However, due to old age and multiple comorbidities being associated with worse outcome in a proportional fashion, it is likely that frailty is a confounding unmeasured factor.51 Diabetes is known to increase the risk of frailty.52 Frailty is a syndrome that is characterised by multisystem, including immune system, dysregulation which leads to reduced physiologic reserve and increased risk of adverse health outcomes including increased susceptibility to severe infections. Frailty has been shown to be associated with poor post-vaccination immune response, increased rates of influenza like illness and laboratory-confirmed influenza infection. 53 In a prospective cohort study in a tertiary hospital investigating older patients (aged ≥65 years) admitted with community acquired pneumonia, nursing home residency (a proxy for frailty) was an independent predictor of viral pneumonia (relative risk {RR} 3.06, P = 0.01) which highlights the role of frailty in institutionalised populations for the increased risk of viral illness. 54 In the British cohort study of patients with diabetes mellitus and COVID-19, the relationship of BMI association with the risk of COVID-19 related-mortality was U-shaped. The risk was greatest for those with very high BMI and the nadir of risk being in those with a BMI 25-29·9 kg/m2. The authors suggested that the higher risks in people with lower BMI could be linked to the effect of confounding by factors that are associated with weight loss which have either not been considered in their analysis. 17 Therefore, frailty may be an unmeasured factor for adverse outcome in people with diabetes and COVID-19.