Nov. 18, 2008

Diet, Supplement Relieve CPT2 Deficiency Symptoms

Seven people with carnitine palmityl transferase 2 (CPT2) deficiency who took a special dietary supplement and followed a prescribed diet for seven months to five years found their exercise-associated muscle pain, as well as dangerous episodes of acute muscle breakdown, resolved.

Without the CPT2 enzyme, compounds called long-chain fatty acids can’t enter cellular structures known as mitochondria, where they normally would be utilized for energy production.

The energy deficit experienced by people with CPT2 deficiency makes exercise difficult or impossible and can cause frequent episodes of rapid muscle destruction that leads to kidney damage. A low-fat, high-carbohydrate diet is a standard therapy, but it’s only moderately effective.

Charles Roe at the Institute of Metabolic Disease at Baylor University Medical Center in Dallas and colleagues, who published their results in the July 22 issue of Neurology, gave study participants a compound called triheptanoin as a substitute for most dietary fat in a special diet.

Triheptanoin is a molecule containing three medium-chain fatty acids (heptanoate) attached to a carbohydrate (glycerol) backbone. Unlike long-chain fatty acids, which require CPT2 or other enzymes to enter mitochondria,  heptanoate can enter these structures by itself.

The study participants, who ranged in age from 10 to 55, ate a diet that was 13 percent protein, 37 percent carbohydrates and 20 percent fat, with triheptanoin oil making up the remaining 30 percent of daily calories. They mixed the oil in foods such as yogurt or pudding and ingested it slowly at each meal and at bedtime, as well as 30 minutes before strenuous activity.

Participants who adhered to the triheptanoin diet avoided hospitalization and muscle breakdown, and only two experienced even mild muscle pain with exercise. All seven reported they could perform strenuous activities, including team sports, swimming, aerobics, skiing and hiking.

Triheptanoin oil is not available except in research studies. However, it has been granted “orphan product status,” which fast-tracks development of drugs for rare diseases, by the Food and Drug Administration.  

Roe and colleagues are collaborating with corporations  to develop a powder form of triheptanoin that can be taken orally or dissolved for use as an intravenous therapy.

Patients with CPT2 deficiency should consult their physicians before taking a dietary supplement or starting a special diet.