TY - JOUR
T1 - Prospective study of body mass index, physical activity and thyroid cancer
AU - Leitzmann, Michael F.
AU - Brenner, Alina
AU - Moore, Steven C.
AU - Koebnick, Corinna
AU - Park, Yikyung
AU - Hollenbeck, Albert
AU - Schatzkin, Arthur
AU - Ron, Elaine
PY - 2010/6/15
Y1 - 2010/6/15
N2 - Increased body size and physical inactivity are positively related to risk of several cancers, but only few epidemiologic studies have investigated body-mass index (BMI) and physical activity in relation to thyroid cancer. We examined the relations of BMI and physical activity to thyroid cancer in a prospective cohort of 484,326 United States men and women, followed from 1995/1996 to 2003. During 3,490,300 person-years of follow-up, we documented 352 newly incident cases of thyroid cancer. The multivariate relative risks (RR) of thyroid cancer for BMI values of 18.5-24.9 (reference), 25.0-29.9 and ≥30 kg m-2 were 1.0, 1.27 and 1.39 [95% confidence interval (CI) 5 1.05-1.85]. Adiposity predicted papillary thyroid cancers (RR comparing extreme BMI categories 5 1.47; 95% CI 5 1.03-2.10) and, based on small numbers, suggestively predicted follicular thyroid cancers (RR 5 1.49; 95% CI 5 0.79-2.82) and anaplastic thyroid cancers (RR 5 5.80; 95% CI 5 0.99-34.19). No relation with BMI was noted for medullary thyroid cancers (RR 5 0.97; 95% CI 5 0.27-3.43). The positive relation of BMI to total thyroid cancer was evident for men but not for women. However, the test of interaction (p 5 0.463) indicated no statistically significant gender difference. Physical activity was unassociated with thyroid cancer. The RRs of total thyroid cancer for low (reference), intermediate, and high level of physical activity were 1.0, 1.01 and 1.01 (95% CI 5 0.76-1.34, p for trend = 0.931), respectively. Our results support an adverse effect of adiposity on risk for developing total and papillary, and possibly follicular thyroid cancers. Based on only 15 cases, adiposity was unrelated to medullary thyroid cancers. Physical activity was unrelated to total thyroid cancer.
AB - Increased body size and physical inactivity are positively related to risk of several cancers, but only few epidemiologic studies have investigated body-mass index (BMI) and physical activity in relation to thyroid cancer. We examined the relations of BMI and physical activity to thyroid cancer in a prospective cohort of 484,326 United States men and women, followed from 1995/1996 to 2003. During 3,490,300 person-years of follow-up, we documented 352 newly incident cases of thyroid cancer. The multivariate relative risks (RR) of thyroid cancer for BMI values of 18.5-24.9 (reference), 25.0-29.9 and ≥30 kg m-2 were 1.0, 1.27 and 1.39 [95% confidence interval (CI) 5 1.05-1.85]. Adiposity predicted papillary thyroid cancers (RR comparing extreme BMI categories 5 1.47; 95% CI 5 1.03-2.10) and, based on small numbers, suggestively predicted follicular thyroid cancers (RR 5 1.49; 95% CI 5 0.79-2.82) and anaplastic thyroid cancers (RR 5 5.80; 95% CI 5 0.99-34.19). No relation with BMI was noted for medullary thyroid cancers (RR 5 0.97; 95% CI 5 0.27-3.43). The positive relation of BMI to total thyroid cancer was evident for men but not for women. However, the test of interaction (p 5 0.463) indicated no statistically significant gender difference. Physical activity was unassociated with thyroid cancer. The RRs of total thyroid cancer for low (reference), intermediate, and high level of physical activity were 1.0, 1.01 and 1.01 (95% CI 5 0.76-1.34, p for trend = 0.931), respectively. Our results support an adverse effect of adiposity on risk for developing total and papillary, and possibly follicular thyroid cancers. Based on only 15 cases, adiposity was unrelated to medullary thyroid cancers. Physical activity was unrelated to total thyroid cancer.
KW - Body mass index
KW - Epidemiology
KW - Physical activity
KW - Prospective study
KW - Thyroid cancer
UR - http://www.scopus.com/inward/record.url?scp=77951931661&partnerID=8YFLogxK
U2 - 10.1002/ijc.24913
DO - 10.1002/ijc.24913
M3 - Article
C2 - 19795465
AN - SCOPUS:77951931661
SN - 0020-7136
VL - 126
SP - 2947
EP - 2956
JO - International Journal of Cancer
JF - International Journal of Cancer
IS - 12
ER -