A recent study featured in the Archives of Gerontology and Geriatrics Plus revealed that 10% of South Asian immigrants over the age of 45 residing in Canada are affected by hypothyroidism. This statistic was determined after adjusting for various sociodemographic factors and health behaviours, showing that immigrants from South Asia are 77% more likely to develop hypothyroidism compared to their Canadian-born peers. Esme Fuller-Thomson, the study’s senior author and a Professor at the Factor-Inwentash Faculty of Social Work, as well as the Director of the Institute of Life Course and Aging at the University of Toronto, highlighted the significance of this finding. She noted that this is likely the first study to demonstrate such a marked increase in hypothyroidism risk among South Asian immigrants, stressing the importance of more proactive thyroid screening in this population.
The consequences of untreated hypothyroidism are severe, ranging from anemia and hypertension to high cholesterol and neurological issues. ZhiDi Deng, the study’s lead author and a medical student at the University of Alberta, suggested an intriguing area for future research. He pointed out that the disproportionately high rates of hypothyroidism among South Asian immigrants might be linked to endemic iodine deficiency in their countries of origin—a well-known cause of the condition. Unfortunately, the survey used in the study did not include data on participants’ iodine levels, which prevented further exploration of this hypothesis.
Dietary habits were also identified as significant factors associated with hypothyroidism. Karen M. Davison, a nutritional epidemiologist and co-author of the study, discussed the dietary connections uncovered by the research. She observed that individuals with lower fat intake or higher consumption of omega-3 fatty acids, fruits, vegetables, and pulses were significantly less likely to suffer from hypothyroidism. This suggests a potential avenue for non-pharmacological, nutrition-based interventions in managing or preventing the disease, though more research is needed to confirm these findings.
Age is another critical factor influencing the likelihood of developing hypothyroidism. Andie MacNeil, a PhD student at the University of Toronto and co-author, noted that individuals over 75 had double the prevalence of the condition compared to those aged between 45 and 55. She attributed this trend to autoimmune thyroiditis, a common cause of hypothyroidism among older adults, which may drive this increased prevalence.
The data for this study was sourced from the Canadian Longitudinal Study on Aging, which analyzed a sample of 26,036 Canadians between the ages of 45 and 85, of whom 1,953 individuals had hypothyroidism. The non-specific symptoms of hypothyroidism, such as fatigue, weight gain, and depression, make it difficult to diagnose without specific blood tests, especially in older adults. This highlights the need for heightened awareness and screening for thyroid conditions to prevent the adverse health effects associated with this disorder.
Esme Fuller-Thomson expressed optimism that these findings would promote increased screening for thyroid conditions among older adults, particularly those of South Asian descent. This proactive approach could help mitigate the severe health outcomes that arise from untreated hypothyroidism. The research sheds light on previously unrecognized risk factors and opens avenues for future studies to explore these risks further and potentially mitigate them.
More information: ZhiDi Deng et al, The relationship between immigrant status, cultural/racial background, and hypothyroidism among middle-aged and older Canadians: An analysis of Canadian Longitudinal Study on Aging data, Archives of Gerontology and Geriatrics Plus. DOI: 10.1016/j.aggp.2025.100129
Journal information: Archives of Gerontology and Geriatrics Plus Provided by University of Toronto
