Working nights? Study flags rising diabetes, hormonal issues

Hyderabad: Around 77% of night shift workers in the city face higher insulin resistance, lower testosterone levels and unhealthy cholesterol levels compared to their day shift counterparts.This finding comes from a recent study by doctors from Gandhi Medical College (GMC), Secunderabad, published in the Indian Journal of Endocrinology and Metabolism (IJEM). The study compared 45 night shift workers with 45 day shift employees from an IT company, analysing metabolic and hormonal markers to understand the impact of shift patterns on health.The results showed that 77% of night shift workers had insulin resistance — a precursor to Type 2 diabetes — compared to 62% among day workers. Notably, this was observed despite night workers being younger on average (28 years versus 31 years) and having lower body weight.Worse metabolic healthLead author Dr Vijay Shekar Reddy, head of endocrinology department at Gandhi Hospital, said the findings challenge common assumptions about fitness. "A striking observation was that night shift workers, though younger and leaner, showed worse metabolic health across multiple markers," he said."Working night shifts is linked to several health problems, including higher triglyceride levels, lower good cholesterol (HDL), reduced levels of LH and testosterone in men, higher estrogen levels in women, and vitamin D deficiency," he added.Doctors attribute these changes to disruption of the body's circadian rhythm — the internal clock that regulates sleep, metabolism, and hormone release. Explaining the biological mechanism, consultant endocrinologist Dr Mujeeb MA said, "Melatonin, which is released at night, is not just a sleep hormone. It also helps repair the body and reduce damage. In people with disrupted sleep, especially night shift workers, melatonin levels drop over time, affecting the repair process."Lower growth harmonesHe further noted that this impacts mitochondria — the body's energy-producing units. "A decline in mitochondrial efficiency can affect growth hormone levels, reproductive hormones, and fat metabolism," he said.The study found that 22% of night shift workers had mild thyroid dysfunction, compared to 11% among day workers. Growth hormone levels were lower in night workers, which is expected as the hormone is mainly released during sleep. Citing earlier research, the study linked low testosterone levels to a higher risk of erectile dysfunction.Doctors cautioned that standard health checks focusing only on weight or waist size may miss these hidden risks. "Night shift workers can have serious metabolic and hormonal issues despite having lower BMI or smaller waist size. This means body weight alone does not reflect their real health risk," said Dr Reddy.Highlighting the lack of India-specific data, the authors stressed the need for better screening and awareness. "Health checks and treatments should not focus only on weight, but also consider circadian rhythm disruption and hormonal changes," Dr Mujeeb added. The findings underline the growing health concerns among night shift workers, especially in sectors like IT, healthcare, manufacturing, and transportation, where overnight work is common.