Is treatment of insulin resistance beneficial independent of glycemia?

Empagliflozin therapy and insulin resistance-associated disorders: effects and promises beyond a diabetic state

Empagliflozin is a SGLT2 inhibitor that has shown remarkable cardiovascular and renal activities in patients with type 2 diabetes (T2D). Preclinical and clinical studies of empagliflozin in T2D population have demonstrated significant improvements in body weight, waist circumference, insulin sensitivity, and blood pressure – effects beyond its antihyperglycaemic control. Moreover, several studies suggested that this drug possesses significant anti-inflammatory and antioxidative stress properties. This paper explores extensively the main preclinical and clinical evidence of empagliflozin administration in insulin resistance-related disorders beyond a diabetic state. It also discusses its future perspectives, as a therapeutic approach, in this high cardiovascular-risk population.

Controversy in diagnosis and management of the metabolic syndrome

Far more work remains to be done to unravel the tangled web of pathophysiology responsible for the metabolic syndrome. This article addresses several aspects of the current controversy surrounding the metabolic syndrome: (1) definition of the metabolic syndrome; (2) evidence for and against the use of the metabolic syndrome as a cardiovascular disease risk predictor; (3) evidence as to underlying pathophysiology; and (4) evidence for treatment of the metabolic syndrome (as opposed to components of the syndrome) in a risk reduction strategy to prevent type 2 diabetes mellitus or cardiovascular disease.

What Is the Metabolic Syndrome?

The metabolic syndrome has been referred to as a clustering of cardiovascular risk factors, including abdominal obesity, atherogenic dyslipidemia, increased blood pressure, insulin resistance, proinflammatory state, and a prothrombotic state. The metabolic syndrome has become one of the leading clinical issues discussed by physicians and the media, leading to increased public awareness to this potentially catastrophic multiplex risk factor for cardiovascular disease. With increasing prevalence in the United States, the metabolic syndrome has been equated to cigarette smoking as a contributing factor to premature cardiovascular heart disease and one of the underlying causes of type 2 diabetes. The identification and modification of the root causes, overweight/obesity, physical inactivity, and the closely associated condition, insulin resistance, needs to be one of the initial strategies that are addressed by the clinician.

Metabolic syndrome and cardiovascular disease

Metabolic syndrome is a constellation of clinical findings that identify individuals at higher than normal risk of developing diabetes mellitus or cardiovascular disease. There are two principal definitions, one emerging from the American National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults, and the other from the World Health Organization. Both definitions share the common elements of abdominal obesity, hypertriglyceridaemia, low HDL-cholesterol, hypertension and abnormal glucose regulation. The syndrome is relatively common across continents, and also among those without marked obesity. It is even more common among patients with major mental health disorders such as schizophrenia. Metabolic syndrome can be used to assess risk for cardiovascular disorder and death, and is an alternative to Framingham Risk Calculations. C-reactive protein may play an additional role in risk prediction. Ongoing monitoring for all components of the metabolic syndrome is necessary. Individuals at high risk require multimodal interventions, including lifestyle interventions and targeted medications as appropriate.

The metabolic syndrome: time for a critical appraisal: joint statement from the American Diabetes Association and the European Association for the Study of Diabetes

The term "metabolic syndrome" refers to a clustering of specific cardiovascular disease (CVD) risk factors whose underlying pathophysiology is thought to be related to insulin resistance. Since the term is widely used in research and clinical practice, we undertook an extensive review of the literature in relation to the syndrome's definition, underlying pathogenesis, and association with CVD and to the goals and impact of treatment. While there is no question that certain CVD risk factors are prone to cluster, we found that the metabolic syndrome has been imprecisely defined, there is a lack of certainty regarding its pathogenesis, and there is considerable doubt regarding its value as a CVD risk marker. Our analysis indicates that too much critically important information is missing to warrant its designation as a "syndrome." Until much needed research is completed, clinicians should evaluate and treat all CVD risk factors without regard to whether a patient meets the criteria for diagnosis of the "metabolic syndrome."

The metabolic syndrome: time for a critical appraisal. Joint statement from the American Diabetes Association and the European Association for the Study of Diabetes

BACKGROUND

The term 'metabolic syndrome' refers to a clustering of specific cardiovascular disease (CVD) risk factors whose underlying pathophysiology is thought to be related to insulin resistance.

METHODS

Since the term is widely used in research and clinical practice, we undertook an extensive review of the literature in relation to the syndrome's definition, underlying pathogenesis, association with cardiovascular disease and to the goals and impact of treatment.

DISCUSSION

While there is no question that certain CVD risk factors are prone to cluster, we found that the metabolic syndrome has been imprecisely defined, there is a lack of certainty regarding its pathogenesis, and there is considerable doubt regarding its value as a CVD risk marker. Our analysis indicates that too much critically important information is missing to warrant its designation as a 'syndrome'.

CONCLUSION

Until much-needed research is completed, clinicians should evaluate and treat all CVD risk factors without regard to whether a patient meets the criteria for diagnosis of the 'metabolic syndrome'.

Potential cardiovascular benefits of insulin sensitizers

A multiple risk factor approach is needed in patients who have type 2 diabetes. Because many risk factors are linked with IR, treatment with insulin sensitizers has the potential to modulate these risk factors favorably. TZDs 'have many important effects beyond lowering blood glucose. By targeting IR, they improve many cardiovascular risk factors that are associated with the IR syndrome. In particular, they increase HDL-C, have anti-inflammatory effects, improve endothelial function and fibrinolysis, and decrease carotid intimal thickness; however, no evidence-based studies on cardiovascular outcomes are available to substantiate the potential cardioprotective effects of TZDs. Several clinical trials that were designed to investigate the effect that these agents have on reducing cardiovascular events are well under way.