Though both eGFRCr and eGFRCys may be unreliable markers of kidney function at extremes of body composition or ill health, eGFRCr more commonly overestimates kidney function in women, and therefore underestimates risk associated with CKD and reduces their eligibility for risk-reduction strategies.43,44 The added value of using cystatin C-based (in preference to creatinine-based) measures for risk stratification for ischaemic stroke and major bleeding is greater in women. Here, CST3 is linked to chronic kidney disease.