Is there any research that defines the roles of glucosamine and chondroitin in elevating lipid levels, especially LDL?—CHRISTY PRICE RABETOY, NP, Piney Flats, Tenn.

Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine and chondroitin taken at full dose over an extended period of time (which is necessary to elicit any therapeutic action) may increase insulin resistance and consequently affect glucose tolerance and other metabolic markers, including lipids.—Sherril Sego, FNP-C, DNP (141-4)