Top POEMs of 2016: Diabetes Mellitus and Obesity

Top 20 POEMs of 2016

Blood Pressure Goal of 140-150 mmHg Best for Patients with Diabetes

Clinical question
What is the appropriate antihypertensive treatment goal for patients with diabetes?

Bottom line
Although most recent practice guidelines have relaxed the blood pressure goals for patients with diabetes, there are a still a few holdouts that suggest aggressive treatment. This analysis shows that the sweet spot for hypertension control in patients with diabetes is between 140 mmHg and 150 mmHg; higher or lower sustained blood pressures increase mortality, the so-called J-curve. (LOE = 1a)(www.essentialevidenceplus.com)

Reference
Brunstrom M, Carlberg B. Effect of antihypertensive treatment at different blood pressure levels in patients with diabetes mellitus: systematic review and meta-analyses. BMJ 2016;352:i717.

Study design: Meta-analysis (randomized controlled trials)

Funding source: Government

Setting: Various (meta-analysis)

Synopsis
These researchers searched 4 databases, including the Cochrane CENTRAL library, identifying 49 studies enrolling 73,738 participants with (mostly type 2) diabetes who were treated for hypertension. Two authors independently selected articles for inclusion and extracted data. Heterogeneity and publication bias were assessed but not reported. Most studies were at low risk of bias. The studies evaluated the effect of hypertension treatment on mortality and cardiovascular events but were not specifically designed to compare benefit across different target systolic blood pressures. So, the authors got creative and looked at mortality rates based on both baseline (before treatment) and attained (after treatment) systolic blood pressure. In patients with a baseline blood pressure greater than 140 mm Hg or greater than 150 mmHg treatment decreased all-cause mortality on average, though not by much (relative risk [RR] 0.88; 95% CI 0.78 - 0.98 and RR 0.89; 0.88 - 0.99). However, cardiovascular mortality, myocardial infarction risk, and development of end-stage renal disease were decreased by 15% to 25%. If baseline blood pressure, however, was less than 140 mmHg, further treatment did not decrease all-cause mortality and significantly increased the risk of cardiovascular mortality (RR 1.15; 1.00 - 1.32). These results are somewhat at variance with a meta-analysis published last year that found a reduced risk of stroke and albuminuria with treatment (JAMA 2015;313:603-615).

Allen F. Shaughnessy, PharmD, MMedEd
Professor of Family Medicine
Tufts University
Boston, MA

Low HbA1C, BP, and Cholesterol in Elderly Patients with DMT2 Associated with High Mortality

Clinical question
Is there an association between mortality and glycemic control, blood pressure levels, and cholesterol levels in patients with type 2 diabetes who are older than 80 years?

Bottom line
Although subject to many of the limitations of cohort studies, the data from this study are consistent with those from many other studies that suggest that elderly patients are worse off with low glycosylated hemoglobin (HbA1C), low blood pressure, and low cholesterol levels. (LOE = 1b)(www.essentialevidenceplus.com)

Reference
Hamada S, Gulliford MC. Mortality in individuals aged 80 and older with type 2 diabetes mellitus in relation to glycosylated hemoglobin, blood pressure, and total cholesterol. J Am Geriatr Soc 2016;64(7):1425-1431.

Study design: Cohort (prospective)

Funding source: Government

Setting: Population-based

Synopsis
These authors evaluated a population-based primary care database in the United Kingdom to identify nearly 26,000 patients older than 80 years with type 2 diabetes. The database includes data on physical examinations, test results, diagnoses, and medications. The researchers mined this database for all they could: clinical data, comorbidities, number of office visits, classes of prescribed medication, smoking status, and so forth. Approximately half the cohort were women, one third had co-existing cardiac disease, and about half had diabetes for at least 10 years. Approximately 10% of the patients were older than 90 years. There was a median of 2 years of follow-up, during which about 4500 patients died (17%, 105 per 1000 person-years). The authors estimated the mortality, adjusting for a variety of factors, including age, sex, and duration of diabetes. Similar to other studies, the relationship between mortality and glycemic control as measured by HbA1C and blood pressure levels follows a U-shaped pattern, with the nadir for HbA1C between 7% and 7.5% (53 - 57 mmol/mol) and for blood pressure between 150/90 mmHg and 155/95 mmHg. For each of these, the mortality progressively worsened with lower and higher HbA1C or blood pressure levels. The relationship between total cholesterol and mortality was more curvilinear, with the highest mortality associated with the lowest cholesterol levels and an asymptotic decrease as cholesterol levels increase.

Henry C. Barry, MD, MS
Professor
Michigan State University
East Lansing, MI

Mediterranean Diet Produces Moderate Weight Loss

Clinical question
What is the effect of a Mediterranean-type diet on body weight?

Bottom line
In addition to improving one's cardiovascular outlook, a Mediterranean diet produces a greater sustained weight loss than does a low-fat diet and a similar weight loss as do other diets in patients who were overweight or obese, most of whom had type 2 diabetes. The range of average weight loss was 3.8 kg to 10.1 kg after one year with a Mediterranean diet versus a loss of 5.0 kg to a gain of 2.9 kg with a low-fat diet. (LOE = 1a-)(www.essentialevidenceplus.com)

Reference
Mancini JG, Filion KB, Atallah R, Eisenberg MJ. Systematic review of the Mediterranean diet for long-term weight loss. Am J Med 2016;129(4):407-415.

Study design: Systematic review

Funding source: Self-funded or unfunded

Setting: Various (meta-analysis)

Synopsis
The so-called Mediterranean diet consists of high consumption of fruits and vegetables; monounsaturated fats, usually from olive oil; moderate consumption of poultry, fish, and dairy; and little or no red meat. To identify studies for this meta-analysis, the authors searched 3 databases, including the Cochrane Library, and identified 5 studies (N = 998) of at least 12 months' duration that investigated the diet's effect on weight loss. The authors also searched reference lists of identified studies, reviews, and other meta-analyses. The included studies were published either in English or French. Several of the studies had high dropout rates, but were otherwise at low risk of bias. Study results were heterogeneous and therefore the authors were unable to combine the results. The patients in the studies were between the ages of 44 years and 67 years and were obese or borderline obese, with an average body mass index (BMI) of 29.7 to 33.5 kg/m^2. Most of the patients in the studies had type 2 diabetes. After 12 months, the Mediterranean diet produced a moderate weight loss, an average range of 3.8 kg to 10.1 kg across the studies, with an average BMI change of -1.0 to -3.33 kg/m^2. These averages were greater than those found with a low-fat diet but similar to a low-carbohydrate diet and an American Diabetes Association diet with similar proportions of protein, fat, and carbohydrates.

Allen F. Shaughnessy, PharmD, MMedEd
Professor of Family Medicine
Tufts University
Boston, MA

POEMs are provided by Essential Evidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, please see http://www.essentialevidenceplus.com(www.essentialevidenceplus.com).

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