To the best of authors’ knowledge, this is the first meta-analysis conducted on the prevalence of diabetes and prediabetes among armed forces personnel. Several investigations have reported the prevalence of diabetes and prediabetes among different components of armed forces. However, the result of these studies has demonstrated a range of variability in the prevalence. The reported prevalence of diabetes in armed forces was varied from 0.0–32.1% or even higher, depending on different diagnostic criteria, age, HDI of countries, special diet, and other environmental factors. The present meta-analysis also indicated that different types of armed forces might play a significant role in the prevalence of dysglycemia.
The obtained results demonstrated that the prevalence of diabetes among the military personnel (7.41%) is lower compare to that of the police officers (13.87%). The highest reported prevalence of diabetes was also related to studies carried out among police officers [16, 19]. The overall prevalence of diabetes among military personnel, not police officers, is under the global prevalence of diabetes (9.30%) [32]. This prevalence is uneven since policemen are expected to be in good shape with regular physical activities. Several previous studies conducted among police officers demonstrated the high prevalence of overweight and obesity made them susceptible to diabetes and heart disease [33, 34]. These risk factors of dysglycemia also were associated with a mean age of study population, and elderly participants were more prone to develop diabetes [34]. These were consistent with the results of meta-regression among police officers.
The most frequent and highly rated stressors might be the other main reasons for the high prevalence of many mental and non-communicable diseases in this occupation group [35, 36]. Moreover, ergonomic problems, long work hours, and particular nutrition regimen should not be underestimated [37, 38]. Recent comprehensive studies also showed the prevalence of metabolic syndrome, and its component is high among policemen relative to the general population [9, 19].
However, the overall prevalence of diabetes among military personnel is lower than that of other components of armed forces. Several studies reported that diabetes only affected less than two percent of this occupational group [22, 28, 30]. In addition to a more appropriate lifestyle, there are some other factors contributing to the low prevalence of diabetes in the military unit. Men are initially recruited at younger ages and undergo regular medical checkups, physical training, and calorie-controlled diets. Then, those individuals with underlying medical conditions, including central obesity, are exempted from these services or replaced in public services [9, 39]. Hence, some included military personnel in the present investigation might have a better health-related quality of life compared to the police officers or the general population [39].
The results also showed that the prevalence of diabetes among this population is associated with the year of study. There are several other studies that indicated the prevalence of diabetes is increasing, passing the time [40, 41]. These are not only related to the increasing trend of physical inactivity and consumption of unhealthy diet but also progression in diagnostic techniques as well as effective strategies for detection and follow-up people with dysglycemia [42].
Our findings demonstrated that the prevalence of prediabetes among the military personnel and the police officers were 7.32% and 6.30%, respectively. A body of evidence has demonstrated a range of prevalence of dysglycemia in armed forces according to different biochemical criteria. Some studies reported a prevalence of impaired fasting glucose about 30–40%, particularly among police officers [16, 19, 27, 43–45]. However, the overall prevalence of prediabetes in included studies is under the estimated prevalence of the adult population (7.30%) around the world [46]. However, the fasting blood glucose should be screened regularly among armed forces personnel, as an affordable and invaluable biochemical factor, and impaired fasting glucose would be better to consider as a critical index for early detection and prevention of at-risk population.