Obesity phenotypes in midlife and cognition in early old age: the Whitehall II cohort study.
OBJECTIVE
To examine the association of body mass index (BMI) and metabolic status with cognitive function and decline.


METHODS
A total of 6,401 adults (71.2% men), aged 39-63 years in 1991-1993, provided data on BMI (normal weight 18.5-24.9 kg/m(2), overweight 25-29.9 kg/m(2); and obese ≥30 kg/m(2)) and metabolic status (abnormality defined as 2 or more of 1) triglycerides ≥1.69 mmol/L or lipid-lowering drugs, 2) systolic blood pressure ≥130 mm Hg, diastolic blood pressure ≥85 mm Hg, or antihypertensive drugs, 3) glucose ≥5.6 mmol/L or medications for diabetes, and 4) high-density lipoprotein cholesterol <1.04 mmol/L for men and <1.29 mmol/L for women). Four cognitive tests (memory, reasoning, semantic, and phonemic fluency) were administered in 1997-1999, 2002-2004, and 2007-2009, standardized to z scores, and averaged to yield a global score.


RESULTS
Of the participants, 31.0% had metabolic abnormalities, 52.7% were normal weight, 38.2% were overweight, and 9.1% were obese. Among the obese, the global cognitive score at baseline (p = 0.82) and decline (p = 0.19) over 10 years was similar in the metabolically normal and abnormal groups. In the metabolically normal group, the 10-year decline in the global cognitive score was similar (p for trend = 0.36) in the normal weight (-0.40; 95% confidence interval [CI] -0.42 to -0.38), overweight (-0.42; 95% CI -0.45 to -0.39), and obese (-0.42; 95% CI -0.50 to -0.34) groups. However, in the metabolically abnormal group, the decline on the global score was faster among obese (-0.49; 95% CI -0.55 to -0.42) than among normal weight individuals (-0.42; 95% CI -0.50 to -0.34), (p = 0.03).


CONCLUSIONS
In these analyses the fastest cognitive decline was observed in those with both obesity and metabolic abnormality.
INSERM, U1018, Center for Research in Epidemiology and Population Health, Hôpital Paul Brousse, Villejuif, France. archana.singh-manoux@inserm.fr
Archana
A
Singh-Manoux
Sébastien
S
Czernichow
Alexis
A
Elbaz
Aline
A
Dugravot
Séverine
S
Sabia
Gareth
G
Hagger-Johnson
Sara
S
Kaffashian
Marie
M
Zins
Eric J
EJ
Brunner
Hermann
H
Nabi
Mika
M
Kivimäki
D000375:Aging / Q000378:metabolism* / Q000523:psychology*; D015992:Body Mass Index; D003072:Cognition Disorders / Q000150:complications / Q000523:psychology*; D015331:Cohort Studies; D048909:Diabetes Complications / Q000523:psychology; D050171:Dyslipidemias / Q000150:complications / Q000523:psychology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000523:psychology; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D009765:Obesity / Q000150:complications / Q000523:psychology*; D050177:Overweight / Q000150:complications / Q000523:psychology; D013997:Time Factors