Effect of changes in waist circumference on metabolic syndrome over a 6.6-year follow-up in Tehran.
OBJECTIVE
This cohort study was conducted to evaluate the effect of waist change on metabolic syndrome (MetS) status and its parameters in 5720 participants, aged >or=20 years, of the Tehran Lipid and Glucose Study who were followed up for a mean of 6.6 years.


METHODS
We measured waist circumference (WC) and MetS parameters at baseline (phase I: 1999) and at follow-up (phase III: 2008), and assessed this relationship across five groups: waist loss (<-2.0 cm); waist stable (-2.0 to 2.9 cm); mild (3.0-5.9 cm); moderate (6.0-8.9 cm) and large (>or=9.0 cm) waist gain. MetS was defined according to the International Diabetes Federation criteria.


RESULTS
In phase I, the mean (s.d.) waist gain was 88.8 cm (11.7). Between phases I and III, the mean (s.d.) waist gain was 5 cm (7.9). There was 16% (95% confidence interval (95% CI): 13.6-18.4) age-adjusted incident MetS and for every centimeter of WC gained over 6.6 years, the risk of MetS increased by 10% (odds ratio (OR) 1.10; 95% CI: 1.09-1.12). Compared with a stable WC in both genders, ORs for MetS for different waist gain groups were as follows: mild (OR 2.3, 95% CI: 1.7-3.2); moderate (OR 3.5, 95% CI: 2.6-4.7) and large (OR 5.8, 95% CI: 4.5-7.6). Waist loss had a protective effect on MetS (OR 0.6, 95% CI: 0.4-0.9). Waist gain showed a detrimental effect on all parameters of MetS in both genders, except for high-density lipoprotein cholesterol and fasting blood sugar in women.


CONCLUSIONS
Waist gain, even mild, was a risk factor of the development of MetS and its parameters. Intervention for reducing WC could be an effective strategy to decrease incident MetS.
Hosseinpanah
F
F
Obesity Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Science, Tehran, Iran. fhospanah@endocrine.ac.ir
Barzin
M
M
Mirmiran
P
P
Azizi
F
F
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D008076:Cholesterol, HDL / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007492:Iran; D008297:Male; D024821:Metabolic Syndrome / Q000209:etiology* / Q000503:physiopathology; D008875:Middle Aged; D056128:Obesity, Abdominal / Q000150:complications* / Q000503:physiopathology; D016017:Odds Ratio; D011446:Prospective Studies; D012307:Risk Factors; D012737:Sex Factors; D055105:Waist Circumference
D001786:Blood Glucose; D008076:Cholesterol, HDL