Abstract:
Diabetes is a significant problem in health care. The problem is growing significantly as worldwide populations are getting older and more obese due to a variety of reasons. The paper reviews current pathophysiological and treatment literature regarding the treatment of diabetes. It focuses primarily on gut hormones and the physiological effects they produce in the disease as well as on surgical methods of diabetes resolution that has varied pathophysiological bases. Novel ways of treatments do not always have fully elucidated rationales for how they work, as bariatric surgeries may have multiple effects on the pathophysiology of the disease and this must be further elucidated. The findings show that while we have come a long way in our understanding of diabetes, there is still more to learn.
Type 2 Diabetes Mellitus is a growing problem worldwide as our population gets older and has easy access to cheap food. What was once thought of as a disease of the rich has crossed over to become a disease of the poor. Characteristically, the pathophysiology of the disease is characterized by impaired insulin secretion, metabolic abnormalities, and hepatic and lipid dysregulation (Harrisons, 2008, p. 2281). Aside from these pathomechanisms of the disease state and besides the vast amount of research dollars spent on the disease, much still remains a mystery. Novel treatment methods also question our understanding of the pathophysiology of diabetes, insofar as that there are methods of treating which can not be fully explained with the current levels of knowledge.
A novel way of managing patients with uncontrolled type 2 DM is through bariatric surgery. Early results appear to be very promising, although the pathophysiological basis for the treatment has yet to be established and needs further investigating (Schauer, et al., 2012). Intestinal hormones are another interesting area to focus research on. Hormones, such as peptide YY (PYY) and glucagon–like peptide 1(GLP-1) play key roles in the mobilization and delivery of fat stores in the body (Fernández-Garcia, et al, 2013). Morbidly obese patients with either impaired fasting glucose or type 2 DM have impaired secretion of PYY and GLP-1, and the consequences of this must be further elucidated. Following surgical intervention, one would assume that levels of PYY and GLP-1 would change and offer further progress the treatment of patients with diabetes, especially considering bariatric surgery has shown positive results in the treatment of type 2 diabetes. However, early results from studies have proven the regulatory systems to be more confusing than once thought, and further investigation is needed to deduce how these hormones work (Reinehr, et al, 2007).
Research by Schauer et al. (2012) has shown that the use of bariatric surgery combined with intensive medical treatment, which consisted of following the guidelines of the American Diabetes Association, a significant number of patients were able to control their glycated hemoglobin levels better then patients that underwent intensive medical therapy alone. Patients that underwent bariatric surgery received either gastric bypass or sleeve gastrectomy (where the esophagus attaches to the intestines,) effectively bypassing the stomach. During sleeve gastrectomy, the volume of the stomach is decreased by 70-80%. It was found by Schauer, et al, that only 12% of patients that underwent medical therapy alone were able to achieve a glycated hemoglobin of ≤6%, while patients that received gastric bypass or sleeve gastrectomy successfully achieved the lowered glycated hemoglobin levels by 42% and 37% respectively. Profoundly shocking was the high number of patients who achieved a glycated hemoglobin of ≤6% with no medication. Zero patients were able to achieve this goal in the group undergoing intensive medical treatment alone, while 42% of patients receiving gastric bypass and 27% of patients receiving sleeve gastrectomy were able to achieve this goal. The conclusions drawn by the researchers indicate that there is a clear connection between controlling diabetes and using surgical methods. It further calls into question our understanding of the gut regulatory systems at play during diabetes.
GLP-1 and PYY are hormones that exert glycemic control and reduce food intake respectively. In a study by Fernández-Garcia, et al. (2013), patients were divided into groups depending on their level of glycemic control. Patients were divided into groups, some having normal fasting glucose (NFG), and others impaired fasting glucose (IFG), and type 2 diabetes mellitus. Patients considered to have a normal fasting glucose were additionally subdivided into a low insulin resistance-NFG and high insulin resistance-NFG groups. Patients were given oral doses of lipid while GLP-1 and PYY values were subsequently measured. Fernández-Garcia et al, showed that patients with a low insulin resistance-NFG had higher levels of GLP-1 and PYY following the fat load. Patients in the other categories showed no significant difference. Considering that PYY is a regulator of the satiety center and its secretion is decreased in patients that suffer from obesity and insulin resistance, it is perhaps not all too surprising that its dysregulation may lead to the development of type 2 DM.
In a similar study that compared GLP-1 levels and PYY levels, Reinehr et al (2007) compared levels of these enteroendocrine hormones in patients before and after bariatric surgery. Patients in their study received either gastric bypass or gastric banding as the weight loss surgery modalities. Results showed that there was no clear-cut connection between levels of these hormones following surgery. Results of the study by Reinehr et al (2007) showed that GLP-1 levels increased and PYY levels decreased which goes against previous ideas that these hormones are released in sync. Patients receiving gastric bypass surgery showed a significant difference with regards to their GLP-1 levels compared to the patients that received only a gastric banding. PYY levels did not show any measured differences when compared between the two procedures. Due to the differences in research methods and the disparities regarding conclusions and how these hormones are regulated, more research to further our understanding of the underlying pathophysiology must be done.
In a review by Rao & Kini (2011) they found that in all types of weight loss surgeries, patients were able to achieve relatively good glycemic control postoperatively compared to what they were able to achieve pre – operatively. In a comparison of duodenojejunal bypass, they reviewed and compared several authors’ results following the surgical interventions. The operative patients were able to reduce HbA1C levels, increase GLP-1 levels, and/or maintain signficant weight loss. Similar results were found when they reviewed the effects of ileal transposition in patients with a BMI <35kg/m2. Results were similar to the above forms of gastric weight loss surgery. In one particular case 86.1% of patients undergoing the operation were able to have complete resolution of their diabetes. In the same study that reported 86.1% of patients underwent resolution of their diabetes, patients showed an increase in PYY values. This contradicts the information found by Reinehr et al (2007), attesting to the fact that more research needs to be done in this subject.
Buchwald et al (2009) also reviewed the connection between weight and type 2 DM after bariatric surgery. They found that overall 78.1% of previously diabetic patients had complete resolution of their diabetes following weight loss surgery, and 86.6% of patients had either excellent control or resolution. Buchwald et al (2009) claims that the largest improvements in patients were seen in those that underwent biliopancreatic diversion/ duodenal switch. Patients that underwent gastric banding had the least improvement of all patients; gastric surgery patients were in the middle. The greater the amount of excess body weight lost, the greater the results. Results post operatively were maintained for two years or more.
While we do not know the effects of surgery on hormones such as PYY and GLP-1, there is a clear association between surgical weight loss and its effects on diabetic patients. Studies need to focus on reasons why it helps, and which procedures work better then others. However, surgery is not the only answer, proper diet, proper oral medication, and proper education about the disease are necessary for the patient to understand that the disease is a lifetime problem, and while special treatments shows promise for resolution of the disease, it is important for the patient to learn how not to go back to their old ways.
With the rising numbers of patients that are either obese, or obese and have type 2DM, nurses must be knowledgeable in the new upcoming trends and treatments in the care of diabetic patients. Nurses should be well versed in the cleaning and dressing of surgical wounds in diabetic patients. They should be able to understand the pathophysiology of type 2 diabetes mellitus and its effects on the body as well as be able to educate patients on the matter and in personal care.
In sum, the pathophysiology of type 2 DM is both well known and still a mystery. The exact mechanisms of glucose control that bariatric surgery helps with are poorly understood. Modern nurses need to be able to help patients manage their disease, which can really destroy quality of life, before it is too late. One of the ways that nurses can help patients take control of their lives is by being up-to-date on all the treatment regimens and the possible genetic and environmental influences that may affect the diseases outcome.
Nurses have the unique opportunity to be able to have a more personalized interaction with the patient than the doctors do,. As such they are in a better position to teach patients about their disease and promote the ways in which they can now be treated.
Works cited:
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DOI 10.1056/nejmoa1200225
