Does NADH inhibit gluconeogenesis?
Yes, this is the effect of metabolizing ethanol and also the reason why excess ethanol can lead to hypoglycemia.

Ethanol is oxidized by the alcohol dehydrogenase to acetaldehyde. This reaction consumes one molecule of NAD+ per molecule ethanol oxidized: 

Ethanol + NAD+ &lt;=&gt; Acetaldehyde + NADH + H+


Acetaldehyde is oxidized by the acetaldehyde dehydrogenase in a second reaction in the mitochondria to Acetyl-CoA, which produces another molecule of NADH:

Acetaldehyde + NAD+  + CoA &lt;=&gt; Acetyl-CoA + NADH + H+


If you now take a look at gluconeogenesis, there is one critical step which needs NAD+: the oxidation of lactate to pyruvate by the lactate dehydogenase which then cannot be processed into oxalacetate, phosphoenolpyruvate and so on. 



Adding excess NADH shifts the reaction equilibrium completely to the side of lactate and also leads to the production of additional lactate, leading to hypoglycemia and lactic acidosis. Excess NADH from the ethanol oxidation inhibits the oxidation of fatty acids in the liver - this process also generates NADH for the production of ATP. NADH signals this process that enough energy is available in the cell. And finally excess NADH also inhibits the malate dehydrogenase reducing the amount of oxalacetate for gluconeogenesis further.