Consequences of metabolic syndrome

In many individuals with insulin resistance, hormonal imbalance and obesity are interrelated, resulting in even more devastating consequences of the metabolic syndrome. Santos and Fonseca found that metabolic syndrome was more prevalent in patients with inflammatory disorders, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis.21

The researchers also discovered increased incidents of atherosclerosis in this same subset of patients. In a post hoc analysis of the Multiethnic Study of Atherosclerosis, Afonso et al discovered that of the four groups studied (no metabolic syndrome and no microalbuminuria, microalbuminuria only, metabolic syndrome only and metabolic syndrome and microalbuminuria), the group with both metabolic syndrome and microalbuminuria had higher levels of inflammatory markers and more subclinical atherosclerosis than the other groups.22

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Further studies have shown that patients with metabolic syndrome demonstrate increased stiffness in precapillary vessels, which impedes subcutaneous microcirculation and makes cardiac events more likely.8 Investigators for the Strong Heart Study proved that patients with metabolic syndrome had a higher in-hospital death rate after acute ST-elevation MI.23 Zhao et al determined that in patients with metabolic syndrome, progression of coronary stenosis was increased by 50% and frequency of cardiovascular events was increased by 64% compared with those without the syndrome.24

In addition to increased cardiovascular risk, metabolic syndrome has been linked to polycystic ovary syndrome (PCOS), sleep apnea, dementia and fatty liver.10 Moreover, recent studies have linked the metabolic factors of obesity, elevated glucose and increased triglycerides to the development of macrosomia, obesity and metabolic syndrome in the unborn child.25,26 Clinicians will have to rethink the care of the pregnant woman, insisting on lifestyle interventions to prevent the passage of unhealthy metabolic conditions to her child.

Tenenbaum and Fisman reported that patients with metabolic syndrome and hyperglycemia had higher mortality rates than patients with the same level of hyperglycemia and no metabolic syndrome; they also reported a 30-day mortality rate of 8.3% vs 2.5% (P <.05), respectively.27

Towfighi, Zheng and Ovbiagele reported that the incidence of stroke has more than tripled for women in the past 20 years, and they attribute this increase to the rising incidence of obesity.28 In a meta-analysis that included 951,083 patients and 87 studies, Mottillo and colleagues found that metabolic syndrome was associated with a twofold increase in cardiovascular outcomes and a 1.5-fold increase in all-cause mortality.29

After analyzing the data from 22,719 individuals in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study, Brown, Voeks, Bittner and Safford found that 47% of the participants had metabolic syndrome.6 With such large numbers of patients falling into the metabolic syndrome category, the need for standardized diagnostic criteria and treatment protocols persists even in the midst of the controversy over the syndrome’s characteristics and utility. 

Screening guidelines 

The assessment of patients suspected of having metabolic syndrome should include a physical examination, a dietary history and laboratory workup.

Physical examination. During the initial visit, measure the patient’s waist and calculate the BMI. Measurement of waist circumference is important because adiposity is related to cardiovascular risk.30 Obesity is defined as a BMI >30, and overweight is defined as a BMI of 25 to 29; a BMI of 18.5 to 24.9 indicates normal weight.31

However, a study of 32,024 participants revealed that the method used to define obesity—whether by body-fat percentage, truncal obesity measurements or BMI — did not change the prevalence of metabolic syndrome, indicating that all measurements were equal.32 Coutinho et al analyzed 16,000 patients with coronary disease and found that increased waist circumference was associated with increased risk of death (hazard ratio [HR], 1.70; 95% confidence interval, 1.58-1.83).33 The study showed that central obesity was associated with an increased risk of death regardless of BMI. Thirty percent of all deaths in the study were attributed to central obesity independently,33 thereby confirming the need to measure both BMI and waist circumference to more adequately determine risk category and tailor treatment to the individual.

BMI can easily be calculated in adults once the height and current weight are plugged into the formula: weight (lb)÷height (in)2×703. The NIH classifications of obesity should be used only as a general guideline, as there are ethnic-specific considerations of obesity that should be applied to each patient.20 Rahman and Berenson found that increased percentage of body fat and obesity among white, black and Hispanic patients corresponded more with a BMI ≥25.5, 28.7 and 26.2, respectively.34 Therefore, counseling on ways to prevent obesity should begin long before the patient reaches a BMI of 30.

After the BMI has been determined, a screening waist circumference should be obtained with the provider standing on the patient’s right side. The patient’s right iliac crest is palpitated and marked, and then a vertical line is drawn from the mid-axillary line. The measuring tape is then placed in a horizontal plane at the level of the mark. The tape should be parallel to the floor and the measurement should be taken during normal respiration.31

According to guidelines in The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7), a screening BP measurement should be taken in the office while the patient is seated, with the arm at the level of the heart.35 Two separate readings are obtained, and elevated readings are confirmed in the contralateral arm. Every office visit should include BP measurement and assessment of risk factors or other comorbidities.

A systolic BP of 120 to 139 mm Hg and diastolic BP of 80 to 89 mm Hg is considered prehypertension. BP readings >130/80 mm Hg in patients with diabetes or kidney disease are a risk factor for metabolic syndrome, and readings >130/85 mm Hg are a risk factor for those without chronic disease. BP readings >140/90 mm Hg require treatment, often with more than one antihypertensive. BP screenings are recommended every two years in patients aged 20 years and older.11

Diet and exercise history. The next step in the assessment for metabolic syndrome is to document a diet and exercise history. Overeating and inactivity are known risk factors for obesity.11 Discussion with patients should address barriers to exercise, support systems and their readiness to change their current regimen.

Open-ended, nonjudgmental questions, such as “How do feel about exercise?” rather than “Do you exercise?” will provide the clinician with more useful information to help determine the patient’s needs; unbiased comments will also help establish trust with the patient.36 Establishing a trusting relationship with the patient can help both patient and provider meet short- and long-term goals for weight loss.