PTH and Huntington disease: As shown in Table 1, in pooled analysis of HD and PD patients, both total CPP and CPP-II counts were higher in diabetics, and correlated strongly with serum phosphate, PTH, intact FGF23, IL-1β, IL-6, sclerostin (an inhibitor of Wnt/β-catenin signalling) and weakly with osteoprotegerin (a soluble decoy receptor for RANKL).