Type 2 diabetes, the most common type of diabetes, is a disease that occurs when your blood glucose, also called blood sugar, is too high. Blood glucose is your main source of energy and comes mainly from the food you eat. Insulin, a hormone made by the pancreas, helps glucose get into your cells to be used for energy. In type 2 diabetes, your body doesn’t make enough insulin or doesn’t use insulin well. Too much glucose then stays in your blood, and not enough reaches your cells.
The classic oral glucose tolerance test measures blood glucose levels five times over a period of three hours. Some physicians simply get a baseline blood sample followed by a sample two hours after drinking the glucose solution. In a person without diabetes, the glucose levels rise and then fall quickly. In someone with diabetes, glucose levels rise higher than normal and fail to come back down as fast.
Type 2 diabetes is often treated with oral medication because many people with this type of diabetes make some insulin on their own. The pills people take to control type 2 diabetes do not contain insulin. Instead, medications such as metformin, sulfonylureas, alpha-glucosidase inhibitors and many others are used to make the insulin that the body still produces more effective.
The Diabetes Control and Complications Trial (DCCT) was a clinical study conducted by the United States National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) that was published in the New England Journal of Medicine in 1993. Test subjects all had diabetes mellitus type 1 and were randomized to a tight glycemic arm and a control arm with the standard of care at the time; people were followed for an average of seven years, and people in the treatment had dramatically lower rates of diabetic complications. It was as a landmark study at the time, and significantly changed the management of all forms of diabetes.
^ Boussageon R, Bejan-Angoulvant T, Saadatian-Elahi M, Lafont S, Bergeonneau C, Kassaï B, Erpeldinger S, Wright JM, Gueyffier F, Cornu C (July 2011). "Effect of intensive glucose lowering treatment on all cause mortality, cardiovascular death, and microvascular events in type 2 diabetes: meta-analysis of randomised controlled trials". BMJ. 343: d4169. doi:10.1136/bmj.d4169. PMC 3144314. PMID 21791495.
With gestational diabetes, risks to the unborn baby are even greater than risks to the mother. Risks to the baby include abnormal weight gain before birth, breathing problems at birth, and higher obesity and diabetes risk later in life. Risks to the mother include needing a cesarean section due to an overly large baby, as well as damage to heart, kidney, nerves, and eye.
Insulin serves as a “key” to open your cells, to allow the glucose to enter -- and allow you to use the glucose for energy. Without insulin, there is no “key.” So, the sugar stays -- and builds up-- in the blood. The result: the body’s cells starve from the lack of glucose. And, if left untreated, the high level of “blood sugar” can damage eyes, kidneys, nerves, and the heart, and can also lead to coma and death.
Morris AP, Voight BF, Teslovich TM, Ferreira T, Segrè AV, Steinthorsdottir V, Strawbridge RJ, Khan H, Grallert H, Mahajan A, Prokopenko I, Kang HM, Dina C, Esko T, Fraser RM, Kanoni S, Kumar A, Lagou V, Langenberg C, Luan J, Lindgren CM, Müller-Nurasyid M, Pechlivanis S, Rayner NW, Scott LJ, Wiltshire S, Yengo L, Kinnunen L, Rossin EJ, Raychaudhuri S, Johnson AD, Dimas AS, Loos RJ, Vedantam S, Chen H, Florez JC, Fox C, Liu CT, Rybin D, Couper DJ, Kao WH, Li M, Cornelis MC, Kraft P, Sun Q, van Dam RM, Stringham HM, Chines PS, Fischer K, Fontanillas P, Holmen OL, Hunt SE, Jackson AU, Kong A, Lawrence R, Meyer J, Perry JR, Platou CG, Potter S, Rehnberg E, Robertson N, Sivapalaratnam S, Stančáková A, Stirrups K, Thorleifsson G, Tikkanen E, Wood AR, Almgren P, Atalay M, Benediktsson R, Bonnycastle LL, Burtt N, Carey J, Charpentier G, Crenshaw AT, Doney AS, Dorkhan M, Edkins S, Emilsson V, Eury E, Forsen T, Gertow K, Gigante B, Grant GB, Groves CJ, Guiducci C, Herder C, Hreidarsson AB, Hui J, James A, Jonsson A, Rathmann W, Klopp N, Kravic J, Krjutškov K, Langford C, Leander K, Lindholm E, Lobbens S, Männistö S, Mirza G, Mühleisen TW, Musk B, Parkin M, Rallidis L, Saramies J, Sennblad B, Shah S, Sigurðsson G, Silveira A, Steinbach G, Thorand B, Trakalo J, Veglia F, Wennauer R, Winckler W, Zabaneh D, Campbell H, van Duijn C, Uitterlinden AG, Hofman A, Sijbrands E, Abecasis GR, Owen KR, Zeggini E, Trip MD, Forouhi NG, Syvänen AC, Eriksson JG, Peltonen L, Nöthen MM, Balkau B, Palmer CN, Lyssenko V, Tuomi T, Isomaa B, Hunter DJ, Qi L; Wellcome Trust Case Control Consortium; Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC) Investigators; Genetic Investigation of ANthropometric Traits (GIANT) Consortium; Asian Genetic Epidemiology Network–Type 2 Diabetes (AGEN-T2D) Consortium; South Asian Type 2 Diabetes (SAT2D) Consortium, Shuldiner AR, Roden M, Barroso I, Wilsgaard T, Beilby J, Hovingh K, Price JF, Wilson JF, Rauramaa R, Lakka TA, Lind L, Dedoussis G, Njølstad I, Pedersen NL, Khaw KT, Wareham NJ, Keinanen-Kiukaanniemi SM, Saaristo TE, Korpi-Hyövälti E, Saltevo J, Laakso M, Kuusisto J, Metspalu A, Collins FS, Mohlke KL, Bergman RN, Tuomilehto J, Boehm BO, Gieger C, Hveem K, Cauchi S, Froguel P, Baldassarre D, Tremoli E, Humphries SE, Saleheen D, Danesh J, Ingelsson E, Ripatti S, Salomaa V, Erbel R, Jöckel KH, Moebus S, Peters A, Illig T, de Faire U, Hamsten A, Morris AD, Donnelly PJ, Frayling TM, Hattersley AT, Boerwinkle E, Melander O, Kathiresan S, Nilsson PM, Deloukas P, Thorsteinsdottir U, Groop LC, Stefansson K, Hu F, Pankow JS, Dupuis J, Meigs JB, Altshuler D, Boehnke M, McCarthy MI; DIAbetes Genetics Replication And Meta-analysis (DIAGRAM) Consortium. Large-scale association analysis provides insights into the genetic architecture and pathophysiology of type 2 diabetes. Nat Genet. 2012 Sep;44(9):981-90. doi: 10.1038/ng.2383. Epub 2012 Aug 12.
Type 2 diabetes has long been known to progress despite glucose-lowering treatment, with 50% of individuals requiring insulin therapy within 10 years (1). This seemingly inexorable deterioration in control has been interpreted to mean that the condition is treatable but not curable. Clinical guidelines recognize this deterioration with algorithms of sequential addition of therapies. Insulin resistance and β-cell dysfunction are known to be the major pathophysiologic factors driving type 2 diabetes; however, these factors come into play with very different time courses. Insulin resistance in muscle is the earliest detectable abnormality of type 2 diabetes (2). In contrast, changes in insulin secretion determine both the onset of hyperglycemia and the progression toward insulin therapy (3,4). The etiology of each of these two major factors appears to be distinct. Insulin resistance may be caused by an insulin signaling defect (5), glucose transporter defect (6), or lipotoxicity (7), and β-cell dysfunction is postulated to be caused by amyloid deposition in the islets (8), oxidative stress (9), excess fatty acid (10), or lack of incretin effect (11). The demonstration of reversibility of type 2 diabetes offers the opportunity to evaluate the time sequence of pathophysiologic events during return to normal glucose metabolism and, hence, to unraveling the etiology.
The first hint that type 2 diabetes is a fully reversible syndrome came from bariatric surgery. Almost a quarter century ago, Pories et al. (12) demonstrated that blood glucose levels normalized in obese people with type 2 diabetes undergoing bariatric surgery and that 10 years later, almost 90% remained free of diabetes. The phenomenon was more recently tested in a randomized prospective study comparing gastric banding with intensive medical therapy for type 2 diabetes (13). This least invasive type of surgery was most suitable for the randomized study, although it was associated with lower rates of diabetes reversal than other procedures. Mean fasting plasma glucose fell to normal levels in the surgically treated group but declined only modestly in the intensive medical treatment group despite oral agents and insulin (Fig. 1) (13). Remission of diabetes was related to the degree of weight loss rather than to group allocation and was achieved in 73% of the surgical group and 13% of the intensive medical treatment group because surgery was more effective in achieving weight loss as previously described (14). Type 2 diabetes can be reversed by applying a surgical procedure that diminishes fat mass.
The apps on Apple's list aren't all from the US, and they don't all target diabetes specifically. While many are tracking and management apps for blood glucose and insulin levels, others are more general purpose apps for eating specific diets, which people with diabetes could benefit from. The list includes mostly consumer-facing apps but one app for doctors, as well as one for kids and one for pregnant women with diabetes.