TIMP3 and chronic kidney disease: This study intended to research the causal relationship of TIMP3 with CKD and markers of kidney function, such as creatinine‐based estimated glomerular filtration rate (eGFRcrea), cystatin C‐based estimated glomerular filtration rate (eGFRcys), eGFRcrea in diabetics (eGFRcrea (DM)) and eGFRcrea in non diabetics (eGFRcrea (No DM)).