Many experts maintain that the conditions associated with metabolic syndrome are connected to one another. Though the exact cause of this syndrome is unknown, many researchers believe that resistance to insulin, a hormone produced by the pancreas to regulate glucose (blood sugar), is a major contributor.

The body relies on insulin to transport glucose from digested food into the cells where it is converted to energy. When the pancreas does not produce enough insulin, or the body is unable to take advantage of its insulin supply, glucose builds up in the bloodstream and cannot enter the cells to provide energy. This condition, known as insulin resistance, sets the stage for type 2 diabetes. For this reason, metabolic syndrome is often referred to as a prediabetic condition, where blood glucose levels are elevated but not yet high enough to be classified as diabetes. Treatments such as exercise and diet can help keep prediabetes from escalating to type 2 diabetes.

It is also believed that the following factors can significantly increase an individual’s risk of developing metabolic syndrome:

• Weight. Several factors related to weight increase a person’s risk of developing metabolic syndrome:
  
  
• Abdominal obesity (sometimes called a “beer belly,” “apple shape” or “central obesity”). Excess fat around the midsection, or a high waist-to-hip ratio. This is a crucial element of metabolic syndrome. Recent research suggests that the tendency to develop visceral fat starting in middle age may decrease levels of a hormone called adiponectin, which can help control levels of glucose and fat.
  
  
• High body mass index (BMI). A BMI of 25 or greater.
  
  
• Low birth weight. Although overnutrition (excess consumption of calories) after birth raises the risk of metabolic syndrome and type 2 diabetes, insufficient nutrition during fetal development also raises their risk, according to the International Diabetes Federation. 
  
  
Age. The risk of developing this condition increases with age. According to the American Heart Association (AHA), less than 7 percent of individuals in their 20s have metabolic syndrome, compared to more than 40 percent of individuals in their 60s. However, experts are noticing an increase in risk factors among school-age children, and the AHA estimates that 4 percent of adolescents ages 12 to 19 have metabolic syndrome.


Race. Risk also varies by racial or ethnic backgrounds. According to the AHA, Mexican Americans have the highest risk of metabolic syndrome (32 percent), followed by white Americans (23 percent), African Americans (22 percent) and “other” racial groups (20 percent). Though there is little difference seen between risks for men vs. women in general, differences are found within certain racial groups. Among African Americans, women have a 57 percent greater risk than men of developing metabolic syndrome. Among Mexican Americans, women have a 26 percent greater risk than men.


• Medical history of diabetes. Individuals are more likely to develop metabolic syndrome if they have a family history of type 2 diabetes or previously had gestational diabetes, a condition that can occur only during pregnancy.
  
  
• Other diseases. Several conditions can increase an individual’s risk of developing metabolic syndrome, including:
  
  
• Polycystic ovarian syndrome. A disorder in which a woman has irregular menstrual cycles and produces extra male hormones.
  
  
• Cardiovascular disease. Diseases of the heart and blood vessels.
  
  
• Dyslipidemia. A condition characterized by any combination of high levels of “bad” LDL or “very bad” VLDL cholesterol, insufficient “good” HDL or elevated triglycerides.

• High blood pressure. A condition in which blood pressure is higher than normal.
  
  
• Gulf War syndrome. The National Health Survey of Gulf War Era Veterans and Their Families has found an elevated incidence of metabolic syndrome, chronic fatigue, joint pain and other disorders in veterans of the Persian Gulf War of 1991.
  
  
• Sleep apnea. Recent research links this sleep disorder to increased risk of metabolic syndrome, insulin resistance and type 2 diabetes.
  
  
• Genetics. Scientists recently found that damage to a gene involved in repairing DNA (the NEIL1 gene) may increase the risk of metabolic syndrome.
  
  
• Stress. Research indicates that chronic stress increases the risk of metabolic syndrome, heart conditions and type 2 diabetes.
  
  
• Low testosterone. Several recent studies have linked low levels of testosterone (male hypogonadism), including that caused by androgen deprivation therapy for prostate cancer, to men’s risk of metabolic syndrome and insulin resistance, in addition to sexual dysfunction.

Individuals who have any of these risk factors are advised to consult their primary care physician or, if there are multiple risk factors, see an endocrinologist.