Dr. Erica Oberg, ND, MPH, received a BA in anthropology from the University of Colorado, her doctorate of naturopathic medicine (ND) from Bastyr University, and a masters of public health (MPH) in health services research from the University of Washington. She completed her residency at the Bastyr Center for Natural Health in ambulatory primary care and fellowship training at the Health Promotion Research Center at the University of Washington.
Environmental factors are important, because even identical twins have only a 30-60% concordance for type 1 diabetes mellitus and because incidence rates vary in genetically similar populations under different living conditions.  No single factor has been identified, but infections and diet are considered the 2 most likely environmental candidates.
Other potentially important mechanisms associated with type 2 diabetes and insulin resistance include: increased breakdown of lipids within fat cells, resistance to and lack of incretin, high glucagon levels in the blood, increased retention of salt and water by the kidneys, and inappropriate regulation of metabolism by the central nervous system. However, not all people with insulin resistance develop diabetes, since an impairment of insulin secretion by pancreatic beta cells is also required.
Diabetes mellitus is a diagnostic term for a group of disorders characterized by abnormal glucose homeostasis resulting in elevated blood sugar. It is among the most common of chronic disorders, affecting up to 5–10% of the adult population of the Western world. The prevalence of diabetes is increasing dramatically; it has been estimated that the worldwide prevalence will increase by more than 50% between the years 2000 and 2030 (Wild et al., 2004). It is clearly established that diabetes mellitus is not a single disease, but a genetically heterogeneous group of disorders that share glucose intolerance in common. The concept of genetic heterogeneity (i.e. that different genetic and/or environmental etiologic factors can result in similar phenotypes) has significantly altered the genetic analysis of this common disorder.
If, on the other hand, you are already starting to develop complications or your medication regimen has changed because your blood sugars are getting higher, remember that diabetes is a progressive disease—and sometimes these things just happen without any influence from your own actions. As you age, beta cells in the pancreas get tired and stop working. If you've had diabetes for 20 years and now need to start insulin, for example, it doesn't mean you've failed. It just means that your body needs some help. Make sure you continue to receive education and that you continue to have someone to lean on when you need it, and keep the lines of communication open with your doctor. It truly can make a difference.
A second oral agent of another class or insulin may be added if metformin is not sufficient after three months. Other classes of medications include: sulfonylureas, thiazolidinediones, dipeptidyl peptidase-4 inhibitors, SGLT2 inhibitors, and glucagon-like peptide-1 analogs. As of 2015 there was no significant difference between these agents. A 2018 review found that SGLT2 inhibitors may be better than glucagon-like peptide-1 analogs or dipeptidyl peptidase-4 inhibitors.