We've been engaging in a conversation on the Track Your Plaque Forum on whether niacin raises blood sugar.
Yes, it does. In the vast majority of instances, however, the rise is trivial and without consequence. Typically, someone will start with a borderline elevated blood sugar of, say, 108 mg/dl. Niacin, 1000 mg per day, then raises blood sugar to 112 mg/dl. This small increase does not oblige any specific action, nor does it pose any excess risk.
Blood sugars in the normal range of <100 mg/dl tend not to show this effect. Higher blood sugars, e.g., 130 mg/dl, may show a more exagerrated effect but it is also rarely of great consequence. People who take medications for adult type II diabetes, or people with childhood-onset, type I diabetes will also experience rises in blood sugar. This is a somewhat larger issue in these people.
Niacin is best undertaken with a change in diet, specifically a reduction in processed carbohydrate foods, particularly evil and ubiquitous wheat products.This will often compensate for the blood sugar effect.
Niacin also shares many of the benefits of weight loss: rise in HDL, drop in triglycerides and small LDL.
Keep it all in perspective: If HDL is low, e.g., 30 mg/dl, or there is a significant small LDL pattern, or you have Lp(a), using niacin--vitamin B3--is quite safe and the most effective treatment we have. It's also a vitamin. Also recall the famous HATS Trial of simvastatin and niacin: simvastatin (Zocor) reduced heart attack risk 30%; adding niacin reduced heart attack risk an astounding 90% .
Very few strategies can yield the enormous benefits, both as a stand-alone treatment or in combination with others, that niacin can, whether or not blood sugar creeps up a few milligrams.