Lifestyle causes of type 2 diabetes

Dietary

The composition of dietary fat intake is linked to diabetes risk; decreasing consumption of saturated fats and trans fatty acids while replacing them with unsaturated fats may decrease the risk. Sugar sweetened drinks appear to increase the risk of type 2 diabetes both through their role in obesity and potentially through a direct effect. A higher proportion of ultra-processed food in the diet was associated with a higher risk of type 2 diabetes in a large ten-year study published in 2019.

Obesity

Obesity has been found to contribute to approximately 55% of cases of type 2 diabetes; chronic obesity leads to increased insulin resistance that can develop into type 2 diabetes, most likely because adipose tissue (especially that in the abdomen around internal organs) is a source of several chemical signals, hormones and cytokines, to other tissues. Inflammatory cytokines such as TNFα may activate the NF-κB pathway which has been linked to the development of insulin resistance. Gene expression promoted by a diet of fat and glucose, as well as high levels of inflammation related cytokines found in the obese, can result in cells that "produce fewer and smaller mitochondria than is normal," and are thus prone to insulin resistance. Fat tissue has also been shown to be involved in managing much of the body's response to insulin and control of uptake of sugar. It secretes RBP4 which increases insulin resistance by blocking the action of insulin in muscle and liver. Fat cells also secrete adiponectin which acts in an opposite way to RBP4 by improving the action of insulin, however, engorged fat cells secrete it in lower amount than normal fat cells. The obese therefore may have higher level of RBP4 but lower level of adiponectin, both of which increase the risk of developing diabetes.

However, different fat tissues behave differently. Visceral fat, which is found around organs such as the intestines and liver, releases signalling molecules directly into blood heading into the liver where glucose is absorbed and processed, while subcutaneous fat under the skin is much less metabolically active. The visceral fat is located in the abdomen in the waist region, large waist circumference and high waist-to-hip ratio are therefore often used as indications of an increased risk of type 2 diabetes.

The increased rate of childhood obesity between the 1960s and 2000s is believed to have led to the increase in type 2 diabetes in children and adolescents.

Sleep

Studies have shown that a reduction in sleep is associated with a significant increase in the incidence of type 2 diabetes. This could account for the increased incidence of diabetes in developed countries in the last decades, since "the causes of this pandemic are not fully explained by changes in traditional lifestyle factors such as diet and physical activity", and "one behavior that seems to have developed during the past few decades and has become highly prevalent, particularly amongst Americans, is sleep curtailment".

In addition, it has been shown that certain minority populations, such as Native Hawaiians/Pacific Islanders or American Indians/Alaska Natives, report higher rates of suboptimal sleep, potentially leading to higher rates of type 2 diabetes.

Prenatal environment

Research also suggests intrauterine growth restriction (IUGR) or prenatal undernutrition (macro- and micronutrient) as another probable factor. Studies of those who were small or disproportionately thin or short at birth, or suffered prenatal exposure during period of famine such as the Dutch Hunger Winter (1944–1945) during World War II, have shown that they are prone to higher rates of diabetes.

Other

Environmental toxins may contribute to recent increases in the rate of type 2 diabetes. A weak positive correlation has been found between the concentration in the urine of bisphenol A, a constituent of some plastics, and the incidence of type 2 diabetes.

References

References

1. (2011). "Williams textbook of endocrinology". Elsevier/Saunders.
2. (2009). "Clinical Obesity in Adults and Children". Wiley-Blackwell.
3. (23 March 2010). "Sugar-sweetened beverages, obesity, type 2 diabetes mellitus, and cardiovascular disease risk.". Circulation.
4. (November 2010). "Sugar-sweetened beverages and risk of metabolic syndrome and type 2 diabetes: a meta-analysis.". Diabetes Care.
5. (January 2009). "Dietary fats and prevention of type 2 diabetes". Progress in Lipid Research.
6. (November 2022). "Saturated Fatty Acid Intake and Risk of Type 2 Diabetes: An Updated Systematic Review and Dose–Response Meta-Analysis of Cohort Studies". [[Advances in Nutrition]].
7. (April 2009). "Lifestyle Risk Factors and New-Onset Diabetes Mellitus in Older Adults: The Cardiovascular Health Study". Archives of Internal Medicine.
8. (June 2001). "Dietary fat intake and risk of type 2 diabetes in women". American Journal of Clinical Nutrition.
9. (16 December 2019). "Ultraprocessed Food Consumption and Risk of Type 2 Diabetes Among Participants of the NutriNet-Santé Prospective Cohort". JAMA Internal Medicine.
10. (19 November 2004). "Prevalence of Overweight and Obesity Among Adults with Diagnosed Diabetes – United States, 1988–1994 and 1999–2002". Morbidity and Mortality Weekly Report.
11. (Mar 2009). "Type 2 Diabetes: Lifestyle Changes and Drug Treatment". AMA Journal of Ethics.
12. (July 2006). "Inflammation and insulin resistance". Journal of Clinical Investigation.
13. (3 September 2009). "The origin of diabetes: Don't blame your genes".
14. (31 May 2007). "The Two Faces of Fat". Nature.
15. (21 July 2005). "Serum retinol binding protein 4 contributes to insulin resistance in obesity and type 2 diabetes". Nature.
16. (15 June 2006). "Retinol-binding protein 4 and insulin resistance in lean, obese, and diabetic subjects". New England Journal of Medicine.
17. (August 2001). "Weight reduction increases plasma levels of an adipose-derived anti-inflammatory protein, adiponectin". [[Journal of Clinical Endocrinology & Metabolism]].
18. (January 2010). "Is the association of type II diabetes with waist circumference or waist-to-hip ratio stronger than that with body mass index?". European Journal of Clinical Nutrition.
19. (July 1992). "Association of waist-hip ratio with diabetes mellitus. Strength and possible modifiers". Diabetes Care.
20. (2003). "Type 2 Diabetes in Children and Adolescents: A Clinician's Guide to Diagnosis, Epidemiology, Pathogenesis, Prevention, and Treatment". American Diabetes Association.
21. (June 2007). "The Metabolic Consequences of Sleep Deprivation". Sleep Medicine Reviews.
22. (23 October 1999). "Impact of sleep debt on metabolic and endocrine function". The Lancet.
23. (2018). "Neighborhood social cohesion and sleep outcomes in the Native Hawaiian and Pacific Islander National Health Interview Survey". Sleep.
24. (2016). "Sleep Duration and Diabetes Risk in American Indian and Alaska Native Participants of a Lifestyle Intervention Project". Sleep.
25. (2019). "Associations of sleep duration with cardiometabolic outcomes in American Indians and Alaska Natives and other race/ethnicities: results from the BRFSS". Sleep Health.
26. (March 2010). "Maternal Micronutrient Deficiency, Fetal Development, and the Risk of Chronic Disease". The Journal of Nutrition.
27. (May 2000). "Fetal nutrition and adult disease". American Journal of Clinical Nutrition.
28. (17 September 2008). "Association of urinary bisphenol A concentration with medical disorders and laboratory abnormalities in adults". JAMA.