Over the years we have had a number or members question the effects of shift-work on the thyroid. Until now, I had no even halfway decent response to make. However, I have just noticed the paper below. The full paper is freely available on PubMed Central.
Ann Occup Environ Med. 2016 Oct 6;28:53. eCollection 2016.
Relationship between thyroid stimulating hormone and night shift work.
Moon SH1, Lee BJ2, Kim SJ1, Kim HC3.
1 Department of Occupational and Environmental Medicine, Inha University Hospital, Incheon, Republic of Korea ; Department of Social and Preventive Medicine, School of Medicine, Inha University, Incheon, Republic of Korea.
2 Department of Occupational and Environmental Medicine, Inha University Hospital, Incheon, Republic of Korea.
3 Department of Occupational and Environmental Medicine, Inha University Hospital, Incheon, Republic of Korea ; Department of Occupational and Environmental Medicine, School of Medicine, Inha University, Incheon, Republic of Korea.
Night shift work has well-known adverse effects on health. However, few studies have investigated the relationship between thyroid diseases and night shift work. This study aimed to examine night shift workers and their changes in thyroid stimulating hormones (TSH) levels over time.
Medical check-up data (2011-2015) were obtained from 967 female workers at a university hospital in Incheon, Korea. Data regarding TSH levels were extracted from the records, and 2015 was used as a reference point to determine night shift work status. The relationships between TSH levels and night shift work in each year were analyzed using the general linear model (GLM). The generalized estimating equation (GEE) was used to evaluate the repeated measurements over the 5-year period.
The GEE analysis revealed that from 2011 to 2015, night shift workers had TSH levels that were 0.303 mIU/L higher than the levels of non-night shift workers (95 % CI: 0.087-0.519 mIU/L, p = 0.006) after adjusting for age and department. When we used TSH levels of 4.5 ≥ mIU/L to identify subclinical hypothyroidism, night shift workers exhibited a 1.399 fold higher risk of subclinical hypothyroidism (95 % CI: 1.050-1.863, p = 0.022), compared to their non-night shift counterparts.
This result of this study suggests that night shift workers may have an increased risk of thyroid diseases, compared to non-night shift workers.
Night shift; Subclinical hypothyroidism; Thyroid stimulating hormone
Full paper freely available here: