People who are obese and also have metabolic abnormality may experience a faster decline in their cognitive skills than others, according to a study.

Among the study subjects, metabolic abnormality was defined as having two or more of the following risk factors: hypertension or taking medication for it, low HDL, hyperglycemia or taking diabetes medication, and high triglycerides or taking medication to lower cholesterol.

The study involved 6,401 people with an average age of 50 at the start of the study. Information on body mass index and the risk factors was gathered at the beginning of the study. The participants took tests on memory and other cognitive skills three times over the next 10 years.

A total of 31% of the participants had two or more metabolic risk factors, while 9% were obese and 38% were overweight. Of the 582 obese people, 350, or 60%, met the criteria for metabolic abnormality.

Over the 10 years of the study, people who were both obese and metabolically abnormal experienced a 22.5% faster decline on their cognitive test scores than those who were of normal weight without metabolic abnormality. Obese individuals who were metabolically normal also experienced a more rapid decline, although the difference was not as dramatic as in obese individuals with metabolic abnormality.

The study appears in the Aug. 21 issue of Neurology, the journal of the American Academy of Neurology. The study abstract is available at www.neurology.org/content/79/8/755.abstract?sid=bc6c82bf-22e5-4920-ae2e-1590834aa1e8.