Metabolism can be split into catabolism and anabolism. Catabolism incorporates all metabolic processes involving the breaking down of molecules, while anabolism describes the synthesis of new, larger molecules from constituents.
If catabolism is not occurring at the required rate, there will be insufficient molecules for anabolism, and this will reduce the rate of biosynthesis. This will likely lead to issues for the organism, especially if the reason for reduced catabolism is because of insufficient starting materials (perhaps due to malnourishment).