A possible consequence of poorly managed diabetes mellitus is an increase in which lab value?

The appropriate lab value that could increase as a consequence of poorly managed diabetes mellitus is creatinine. In diabetes, hyperglycemia can lead to kidney damage over time due to diabetic nephropathy. This condition affects the kidneys' ability to filter waste properly, causing elevated creatinine levels, which indicate impaired kidney function.

While it's true that LDL levels can be affected by poor metabolic control in diabetic patients, the more direct and established consequence of unmanaged diabetes is the decline in renal function, which is reflected by rising creatinine levels. Elevated LDL cholesterol can be a result of poor overall metabolic syndrome, but it is not as closely tied to the immediate complications arising from diabetes as is the impact on kidney function and consequent creatinine levels. Therefore, for this specific question regarding the consequences of poorly managed diabetes, the increase in creatinine is a more accurate answer.