Tom, it does seem that any marginal increase of HDL from niacin does not seem to correspondingly decrease CV risks. Perhaps, Here
is why. Statins will not increase the HDL, but by decreasing the LDL, possibly less "need". I've been on varying doses of three statins, with the most potent decreasing my HDL~20 and the HDL-particles were halved. So I returned to the minimal dose of a weak statin and stopped the niacin, with the HDL values back to my pre-statin levels.
You might like to post your cholesterol and the A1c labs. The latter does seem to climb up slightly on statins, which as we know is a disturbing trend.