Diabetes mellitus is a complex, chronic illness requiring continuous care with multi-factorial risk reduction strategies along with glycemic control, which is characterized by hyperglycemia, glycosuria, hyperlipidemia, and negative nitrogen balance and often ketonaemia results from defects in insulin secretion, insulin action or both leading to impairment the metabolism of carbohydrates, lipid and proteins causing damage, dysfunction, and failure of different organs. <br /> Smoking is one of the most important risk factors associated with diabetes. In fact, smokers are 30–40% more likely to develop type 2 diabetes than nonsmokers. Smoking increases inflammation in the body. Inflammation occurs when chemicals in cigarette smoke injure cells, causing swelling and interfering with proper cell function. Smoking also causes oxidative stress, a condition that occurs as chemicals from cigarette smoke combine with oxygen in the body. This causes damage to cells. Evidence strongly suggests that both inflammation and oxidative stress may be related to an increased risk of diabetes. The evidence also shows that smoking is associated with a higher risk of abdominal obesity, or belly fat. Abdominal obesity is a known risk factor for diabetes because it encourages the production of cortisol, a hormone that increases blood sugar. Smokers tend to have higher concentrations of cortisol than nonsmokers. Nicotine is considered to be as the major pharmacologically active chemical in tobacco is responsible for the association between cigarette smoking and development of diabetes because the functional nicotinic receptors are present in pancreatic islets and β-cells, which in turn negatively affect pancreatic β-cell function and may increase apoptosis of islets β-cells increasing sympathetic nerve activity, with elevation of vascular tone, increases energy expenditure, secretes corticoids, and leads to heart overburden, the heavy smokers at least 20 cigarettes daily had a 61% higher risk, while less than 20 cigarettes daily were correlated to a 29% increase of risk. <br /> Smoking is associated with multiple complications of diabetes. Nephropathy (kidney disease) has been shown to be common in Type 1 diabetic patients who smoke29 and smoking increases the risk of albuminuria in both types of diabetes.30 31 (Albuminuria refers to the presence of protein in the urine and can indicate signs of kidney disease.) Another small study of 33 people with Type 2 diabetes with kidney disease found that smokers’ kidney function declined more rapidly than that of non-smokers, despite drug treatment, suggesting that smoking cessation could slow the progression of kidney disease in people with diabetes who use ACE inhibitors. The relationship between cigarette smoking and retinopathy (disorders of the retina) is less well defined than that of other microvascular complications of diabetes. However, some studies have found an association between smoking and diabetic retinopathy. Smoking is also a documented risk factor for both the development and progression of various types of neuropathy (damage to the peripheral nervous system). A retrospective case control study of type 1 and type 2 diabetic patients found that current or ex-smokers were significantly more likely to have neuropathy than individuals who never smoked (64.8% vs. 42.8%). A more recent prospective study found that cigarette smoking was associated with a 2-fold increase in risk. <br /> <br /> Stopping smoking reduces the risk of cardiovascular disease, lung disease, cancer and stroke. As diabetes also increases the risk for heart disease and stroke, smokers with diabetes are strongly advised to quit. However it appears that many smokers with diabetes are not receiving this advice. One possible explanation for the lower quitting rates among people with diabetes is the fact that stopping smoking is associated with weight gain and this is likely to be of concern in people who have diabetes and are already overweight.