Diabetes is a metabolic disorder affecting a large segment of the population worldwide, cutting across nationalities in both developed and developing countries. It not only disturbs the body’s glucose balance but also affects every organ system, including the circulatory system. ALSO READ: Aging skin got you scratching? Here’s what to do The circulatory system consists of a pump—the heart—which circulates blood throughout the body. Oxygen-rich blood is carried from the heart through blood vessels called arteries to all parts of the body. Deoxygenated (impure) blood returns to the heart through veins, is sent to the lungs for oxygenation, and then brought back to the heart. There is an extensive network of blood vessels—large, medium, small, and very small—that connect to every part of the body, reaching virtually every millimetre. This entire system normally functions smoothly; however, long-standing diabetes disrupts it and impairs blood circulation. ALSO READ: Ringing in the ears? It could be tinnitus, an often-ignored problem Persistently high blood sugar in uncontrolled diabetes causes stress and inflammation of the inner lining of blood vessels. Over time, this leads to stiffening and narrowing of the vessels. They become less elastic due to the formation of harmful chemical end products resulting from chronic inflammation and oxidative processes. ALSO READ: A mother and daughter’s fight against diabetes in Rwanda Diabetes also promotes cholesterol deposition in the walls of blood vessels, further narrowing their lumen and restricting blood flow. Involvement of these vessels affects blood supply to vital organs, which may result in kidney failure, heart failure, or heart attack. ALSO READ: How diabetes impacts digestive health Reduced blood flow, particularly to the legs and feet, increases the risk of peripheral artery disease (PAD). This condition typically presents as painful cramps in the legs or feet while walking. The pain subsides with rest and recurs upon resuming walking. Poor circulation also delays wound healing. In severe cases, gangrene may develop, sometimes necessitating amputation of the affected limb. Smoking and tobacco use further increase the risk of peripheral artery disease in individuals with diabetes. Damage to small blood vessels can lead to retinopathy, which affects the retina—the light-sensitive screen of the eye on which images are formed. This may manifest as blurred vision, dark spots before the eyes, or impaired night vision. Similarly, reduced blood flow to the kidneys can result in chronic kidney disease. The nervous system is also affected due to impaired blood supply to the nerves. Small blood vessels that nourish the nerves become damaged, compromising circulation. Peripheral nerves—responsible for sensation in the limbs—are usually affected earliest. This leads to abnormal sensations such as tingling and numbness. In more severe cases, loss of sensation in the feet may occur, increasing the risk of unnoticed wounds and ulcers. Because of poor circulation, these wounds often heal slowly. Involvement of the autonomic nervous system may result in altered bowel habits, such as recent onset of diarrhoea or constipation, low blood pressure, and other related symptoms. Among the most distressing complications are erectile dysfunction in men and reduced sexual function in women. Poor blood flow to peripheral tissues places additional strain on the heart, as it must work harder to meet the body’s demands. Over time, this can weaken the heart muscle and impair its function, leading to heart failure. If hypertension, lipid abnormalities, or obesity coexist with diabetes—a combination often referred to as metabolic syndrome—the risk of heart failure is further increased. Certain complications, such as peripheral neuropathy, may develop over time in long-standing diabetes, even when blood sugar levels are reasonably controlled. The longer the duration of elevated blood glucose, the greater the risk of damage to the heart and blood vessels. In many instances, diabetes is diagnosed only after one of these complications becomes apparent as a result of circulatory damage. Prevention lies in early detection and effective control of diabetes. Treatment depends on the specific organ affected and the clinical manifestations present. Dr. Rachna Pande is a specialist in Internal Medicine.
