Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice. Cardiac dysfunction may lead decresed pumping capacity of blood which may reach periphery decresed lead lactic acid accumulation lead to fatigue. Also in diabetic patients fatigue may be due to wide spread inflammation or depression or insomnia or hypothyroidism or poor kidney function or poor nutrition and lack of social support etc. Until examination is done it is difficult to say what it is. Please check your thyroid, testosterone, electrolyte, hemoglobin, vitamin d status and get treated accordingly. Please consult your physician he will examine and treat you accordingly. Hope I have answered your query. Let me know if I can assist you further.