Iodine deficiency a contributing factor to osteoporosis in postmenopausal women
Levels of urinary iodine concentration appear to be lower in women with postmenopausal osteoporosis than in healthy postmenopausal women, suggesting the involvement of iodine deficiency in osteoporosis in this population, according to a study.
The study included 132 participants who were grouped as follows: healthy postmenopausal women (n=34; mean age 54.1 years; mean body mass index [BMI], 31.3 kg/m2), osteopenic women (n=38; mean age 56.6 years; mean BMI, 30.4 kg/m2) and women with postmenopausal osteoporosis (n=60; mean age 56 years; mean BMI, 28.6 kg/m2).
None of the participants had secondary osteoporosis, received drugs or hormones influencing bone metabolism within the last 6 months, were smokers or were alcohol users.
Demographic, clinical and laboratory findings were examined and compared among the three participant groups. Resulting data revealed that urinary iodine levels were highest in the control group and decreased, in order, in the osteopenic and postmenopausal osteoporosis groups (216.1 vs 154.6 vs 137.5 μg/L; p<0.001). These differences remained significant after controlling for BMI (p<0.001).
Of note, urinary iodine level significantly correlated with the total T-score for the lumbar spine on multiple regression analysis adjusting for BMI, alkaline phosphatase isoenzyme and urinary deoxypyridinoline (p=0.006).
The present data highlight iodine deficiency as a potential factor that contributes to the development of osteoporosis in postmenopausal women, researchers said.
While the particular iodine metabolic pathways that affect bone mineral density during the postmenopausal period are unknown, available evidence points to a correlation between iodine deficiency and increased oxidative stress. Severe iodine deficiency has been shown to result in increased oxidative stress and higher level of oxidative damage to DNA. Increased oxidative stress has also been highlighted as one of the mechanisms underlying osteoporosis. [Rheumatol Int 2008;28:317-321]
Additional studies with a greater number of participants are warranted to confirm the current findings, researchers added.