Causes and Symptoms of T2DM

Type 2 diabetes, also called non-insulin-independent diabetes mellitus or T2DM, is a non-communicable disease prevalent in society today (Tripathi & Srivastava, 2006). It is the sixth highest cause of disability and is included as one of the top ten death causes globally (GBD 2015 Disease and Injury Incidence and Prevalence Collaborators, 2016). In 2017, out of the 608 million diagnosed and undiagnosed diabetes patients, over 90% were affected by T2DM. By the year 2040, authorities estimate global morbidity of 642 million with T2DM (Chatterjee et al., 2017; IDF Diabetes, 2019).

T2DM is caused by pancreatic B-cell dysfunction leading to insulin deficiency in patients. In the human body, insulin primarily works to regulate blood sugar levels and store the glucose from the broken-down carbohydrates to use as energy later on (​​NCD Risk Factor Collaboration (NCD-RisC), 2016). This insulin deficiency leads to patients experiencing symptoms such as unintentional weight loss, extreme thirst and hunger, numbing of hands or feet, and more.

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Additionally, T2DM can cause serious microvascular and macrovascular complications that can lead to the distress of patients and their families (Chatterjee et al., 2017). Examples of these complications include retinopathy, cardiovascular disease, and pancreatic cancer. Cardiovascular disease is the most prevalent complication, greatly contributing to the global mortality of the disease by multiplying the risk of death by at least 3 times (Gæde et al., 2003; Stamler et al., 1993). Although early detection of the disease reduces the risk of complications, most diabetes patients still experience these complications due to the delay of diagnosis (Chatterjee et al., 2017; Harris et al., 1992). The symptoms are usually noticed after several years of disease development, at times up to 12 years, making early detection and prevention more difficult (Centers for Disease Control and Prevention [CDC], 2021a).

  The epidemiology of T2DM is affected mainly “by genetic and environmental factors” (Chatterjee et al., 2017, p. 2240). When relating genotype and phenotype amongst the patients, a common genetic trait was found for 10% of the patients. This genetic trait was more clearly exhibited when patients were in an obesogenic environment with risk factors (Grarup et al., 2014; Jenkinson et al., 2016). 

References [Part I, II, and III]