Smoking, diabetes and hyperlipidaemia

The epidemiological evidence linking smoking with insulin resistance is con siderable. This evidence is even more convincing because there is a dose re sponse relationship between smoking and the risk of non-insulin dependent d iabetes (NIDDM). Similarly, there is a time-dependent decrease in risk of N IDDM for those who quit smoking. Insulin resistance (in the form of impaire d glucose tolerance, IGT) may precede the development of NIDDM. There is a biochemical basis for the smoking- IGT / NIDDM relationship. Smoking increases the risk of developing diabetic complications like nephro pathy, neuropathy and retinopathy. Smoking is also an independent risk fact or for myocardial infraction and all-cause mortality in NIDDM. Smokers are both insulin resistant and lipid intolerant. Smoking cessation increases circulating high density lipoprotein (HDL) and reduces low densit y lipoprotein(LDL) levels, despite weight gain. Those providing advice or treatment to improve cardiovascular risk factors should be aware of these smoking-related harmful effects. This is especiall y true if IGT is underdiagnosed despite the fact that this condition increa ses the risk of vascular events. Explaining that smoking increases the chan ce of developing diabetes as well as raising 'blood fat' levels may convinc e more smokers to quit.