The American Epidemic
Childhood Obesity, Diabetes Mellitis Type 2, and the Next Generation
In 2004 U.S. Surgeon General, Richard H. Carmona, stated the present generation will be the first not to outlive the previous generation, and the first to have a lower quality of life directly due to their health . The culprits of this prognosis are obesity and Diabetes Mellitis type 2 secondary to obesity. Nationally and internationally obesity is developing into an epidemic. Previously malnutrition has been considered a problem of third world countries, but it is now one of the leading concerns of this country as well as other first world countries such as the United Kingdom, Japan and Australia. Due to the wide array of associated health problems obesity is considered to be a contributing factor of many of the leading causes of death in this country including heart disease, stroke, respiratory disorders, diabetes, kidney failure, and some cancers. Diabetes itself is a contributing factor to cardiovascular disease and kidney failure. As of 2005, an estimated 176,500 people under the age of 20 had Diabetes Mellitis Type 2. Many are as yet undiagnosed, but the expectation is that currently there are 1 out 4-6 hundred children with this disease, particularly in African American, Native American, and Hispanic American groups. As this trend continues to grow it is necessary to understand the long term effects this will have for today’s children. As it is such a recent problem, not even cited in the literature until the 1980’s, there is very little natural history of Childhood Diagnosed Type 2 Diabetes Mellitis.
Childhood Obesity and Diabetes
Obesity in children has been contributed to a more sedentary lifestyle accompanied with less nutritious diets. It is estimated that the average American child spends more than four hours a day looking at some kind of screen. Meals frequently come from “fast food” establishments with documented high fat, high carbohydrate, low fiber, low protein, and large portion meals. Many Asian countries and a growing number of African countries that are experiencing a “westernization” of diet are seeing similar spikes in childhood and adult obesity.
There is substantial evidence linking obesity with Type 2 Diabetes. According to numerous reports, approximately 85% of children with Type 2 Diabetes are obese or overweight according to their physician. Since obese and overweight children are 70% more likely to be overweight or obese as an adult compared to their normal weight counter parts, and 85% more likely if a parent is overweight or obese, even if a child does not develop diabetes during their youth, the risk is great that they will be diagnosed as an adult. Risk increases if a first or second degree family member has Type 2 Diabetes.
Diabetes Mellitis Type 2
Diabetes Mellitis is a condition that results from an inability of the body to utilize glucose due to a problem associated with insulin. For Type 2, and most Non-Type 1 conditions of diabetes, this occurs because of an insulin resistance. As insulin accumulates, because insulin receptors are not moving insulin across the cell, insulin production declines. This turns into a “downward spiral” where resistance increases and production decreases. Comparatively, type 1 results from an autoimmune attack on the β-cells of the pancreas responsible for insulin production. In type 2 diabetes, a hormone released by the jejunum or duodenum of the small intestine may affect insulin resistance. This is indicated by the nearly 100% improvement of type 2 diabetes in patients who undergo gastric bypass surgery which removes the duodenum and jejunum from normal activity.
Type 2 diabetes is genetically independent of type 1 diabetes.
“The insulin-dependent juvenile-onset form (IDDM) [Type 1 Diabetes] and the non-insuin-dependent maturity-onset from (NIDDM) [Type 2 Diabetes], appear to be genetically different. Family studies suggest that each type “breeds true”, and studies in monozygotic twin pairs show that only about 50 percent are concordant with respect to IDDM, whereas close to 100 percent are concordant for NIDDM.”
Type 2 diabetes is also genetically different from a similar and rare non-type 1 diabetes called Mature Onset Diabetes of the Young (MODY). This condition is known to have a single affected allele, while type 2 diabetes is the result of multiple affected alleles. Symptoms and treatment of MODY is similar to that of type 2 diabetes and may be a reasonable guide for treatment of children with type 2 diabetes.
The two most significant risk factors for type 2 diabetes in children are obesity and heredity.
“16% of children aged 6 to 19 years are considered overweight. The report also points out that this percentage has tripled since 1980. An estimated 85% of children with type 2 diabetes are overweight or obese when the disease is diagnosed. A high body mass index (BMI) is the first criteria for screening children and adolescents for type 2 diabetes”
While all obesity is cause for concern, obesity considered to be “central obesity” is of the most concern and is characterized as visceral fat. Both insulin resistance and decreased insulin secretion, according to Copeland, are related to an increase in visceral fat. Insulin resistance itself increases both with increased obesity and, for obese and non-obese children, during puberty.
Accompanying insulin resistance is hyperinsulemia, a condition attributed to compensation for insulin resistance. As insulin resistance increases, insulin production initially increases and insulin appears at higher concentrations in the blood. For a child with an already high resistance to insulin, the natural increase in insulin during puberty may overextend the β-cells capability to produce insulin and diabetes results. Because of this, the majority of child-hood diagnosed type 2 diabetes appears to develop during puberty years.
Heredity itself is a strong risk factor for type 2 diabetes, however accompanied with obesity, the risk is significantly high. For a patient with a first degree relative with type 2 diabetes and diagnosed as obese, it is a high probability that they will develop diabetes at some point in their life. According to the CDC one-third of this generation will develop type 2 diabetes during their life, undoubtedly due to the trends in obesity.
Initially a patient may be asymptomatic. The first indicators of diabetes will generally be excessive thirst and polyuria. As the disease progresses untreated, there will be increased hunger accompanied by potential weight loss, as tissues don’t receive the energy they need. Continued progression may see fatigue, blurred vision, and increased healing time for even small wounds. As the disease continues without treatment or diagnosis there is increased likelihood of seeing acute complications, which may be fatal.
Acute and Chronic Complications
Three types of acute complications can occur with type 2 diabetes, diabetic ketoacidosis, hyperosmolar nonkitotic state, and hypoglycemia. Diabetic ketoaciosis (DKA), which is more common in type 1 diabetes than type 2, results when too little insulin is present. Ketone bodies build up decreasing pH of the blood; once pH drops below 6.7 the condition is fatal. It is generally a very rapid onset condition. Most DKA events occur in new or undiagnosed patients who do not adequately control insulin levels. For type 2 diabetics, DKA is an increased likelihood when the condition has progressed to insulin dependence.
Hyperosmolar nonketotic state (HNS), often called hyperglycemia, also occurs when there is an insufficient amount of insulin available. In HNS, however, the problem is not ketone build up, as with DKA, but rather an increase in osmolarity of glucose leading to polyuria, which will ultimately lead to hypovolemia. In DKA, insulin is virtually absent, however in HNS there is enough insulin to inhibit lipolysis, preventing ketone build up. HNS can be fatal and occurs more frequently in type 2 diabetics.
Hypoglycemia occurs when there is too little glucose in the body. Because the brain requires glucose for normal functioning, hypoglycemia directly affects behavior and consciousness. Hypoglycemia is a slower building condition than DKA or HNS since there are additional stores of glucose to access when hypoglycemia initially presents. Although potentially fatal, hypoglycemia is usually easily treated by providing the patient with a sugar source. Oral glucose, intravenous dextrose, and any sugar containing food item may be used to do this.
Chronic complication of type 2 diabetes can be divided into three categories: microangiopathic conditions, macrovascular conditions, and other conditions and side effects. Microangiopathic conditions are diabetic retinopathy, diabetic nephropathy, and diabetic neuropathy. Diabetic retinopathy occurs as new blood vessels hemmorhage due to weakening of the vessel. It is the leading cause of blindness in the United States and affects 80% of diabetics with a usual onset of approximately ten years after development of diabetes, though ophthalmologists believe that proper eye care could prevent many cases. Diabetic nephropathy has a similar pathology as retinopathy but occurs in the kidneys. It has a typical onset of approximately 15 years after onset of diabetes. It is the leading cause of end-stage renal disease (ESRD), a condition marked by complete failure of kidney function. Without dialysis or transplant, ESRD is fatal. According to one study, 6% of patients studied with childhood diagnosed type 2 diabetes were on dialysis. In the same study, 9% were deceased, some (though the percent was not indicated) due to ESRD directly attributed to type 2 diabetes. Diabetic neuropathy is degeneration of nerves which leads to impaired sensation. This may be as minor as pain in the extremities and slowed digestion, to chronic conditions such as carpal tunnel disease. Most disturbing however is the result of neuropathy on injuries. Because there is lost sensation, many injuries, which are slow to heal due to diabetes, remain untreated, become infected by opportunistic bacteria, and become ulcers. Many develop gangrene. Diabetic neuropathy is the leading cause of non-traumatic amputation of the limbs in the US.
Macrovascular conditions associated with type 2 diabetes are Cardiovascular disease (CVD), Peripheral Vascular Disease (PVD), and diabetic myonecrosis. CVD leads to Storke, a condition the presents 2-4 times more often in diabetics, and Coronary Artery Disease (CAD) which causes 65% of deaths of diabetics.
“An avalanche of cardiovascular disease (CVD) in children with Type 2 diabetes is approaching.
“There is little data on the long-term follow up of childhood onset Type 2 diabetes given the relatively recent onset of the problem. However, the early description of outcomes is concerning. Sudden cardiovascular death has been reported in the third decade of life in young adults with childhood-onset Type 2 diabetes. Given that the artheroslerotic process begins early in life, it seems reasonable to assume that dyslipidemia in children with Type 2 diabetes posess a significan risk for the development of early CVD. Longitudinal, prospective surveillance witll be required to confirm this.”-Sellers
PVD leads to many conditions, most notably atherosclerosis which leads to thrombis and embolism, conditions of ischemia that may fatally affect the lungs, heart, and brain. Diabetic myonecrosis occurs when muscles, usually of the thigh, lack enough blood
supply to effectively manage function.
Other associated conditions are periodontal disease, for which young adults with diabetes are twice as likely to have than non diabetics; acanthosis nigricans, a darkening of skin tissue at the nape and axillae due to unused insulin invading and discoloring the tissue. Lastly, diabetics have a higher susceptibility to illnesses, and, once ill, have worse prognoses in healing time and mortality, leading to many deaths due to usually treatable illnesses such as pneumonia and flu. In all, most of these conditions may be fatal, and most diabetics, particularly those who do not manage their condition appropriately, will die from one of these conditions. In 2002, according to the CDC and HHS, diabetes was the 6th leading cause of death in the US with more than 73 thousand people dieing directly because of diabetes, and over 224 thousand people dieing from a condition which diabetes contributed to.
Traditionally, treatment for type 2 diabetes has been diet and exercise, and pharmaceuticals, using insulin and insulin-type drugs for sever cases of highly limited insulin production. Recently gastric bypass has been largely successful. For children however, it is difficult to determine the safe and effective treatment. Many pharmaceuticals have been found to be inappropriate for treating children and the FDA approves only insulin and metformin. Unfortunately metformin is contraindicated for patients with renal conditions, which, as mentioned, is a condition frequently associated with diabetes. Diet and exercise, which in adults can almost completely manage or prevent diabetes with just a 5-7% body weight loss, is not effective for managing diabetes in more than 10% of children, though it has been successful in prevention of diabetes. The severity and complications associated with gastric bypass eliminate this as a reasonable treatment for children. The problem with treatment for children with type 2 diabetes is the assumption that what is okay for adults is okay for children or that what is effective for type 1 will be effective for type 2.
“The medical literature is rife with examples of adverse outcomes that have resulted from the extrapolation of adult data into the pediatric population”- Sellers
“Despite an often “adult” body size, children and adolescents must not be treated simply as younger adults. The use of adult appropriate diabetes educational materials is often not helpful, and the use of type 1 diabetes educational materials for children or adolescents with type 2 diabetes is inappropriate and occaisssionally destructive.”-Copeland
Besides the impact these odds have on the individuals most at risk, there is a nationwide burden due to diabetes. Not only are the medical costs high, the loss of productivity will be sharply felt in the next generation as masses of people will be unavailable for necessary jobs such as service positions in fire, police, and emergency departments, as well as military positions based solely on their incapability to function as such. Financially, the US spent 132 billion dollars in 2002 in direct (92 billion dollars) and indirect (40 billion dollars) costs; indirect costs are associated with disability, work loss, and premature mortality.
While there has been an increase in social response, particularly to obesity and subsequently to diabetes, there have been few proactive attempts to eradicate, or even alleviate the problem. The Center for Disease Control (CDC) and the National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK) have establish two research projects, SEARCH and SEARCH II to develop understanding and action plans to the epidemic. SEARCH, which was completed in 2005, has accumulated data relating to trends and was the first massive diabetes research project in the US to view the problem as a community whole as opposed to a race by race problem. Reviewing the data lead to the development and funding of SEARCH II which plans to be complete in 2009 and hopes to have some longitudinal natural history data to present the long term outlook and hopeful prevention of childhood diagnosed type 2 diabetes.
There are programs being developed in schools and by communities to improve nutrition and encourage a more physically active lifestyle in adults and especially children. Many soft drinks, nutritionally hollow fruit juices, and candy have been removed from schools and many community centers have physically engaging activities for youth available. Some corporations have even assisted, such as one corporation that provides “SMART” choices and information. Little legislation has been passed, but Secretary Thomson of Health and Human Services recently (2006) adjusted nutrition label requirements, requiring transfat information to be present . Although not a direct problem of diabetes, it is related to obesity.
Currently there is no hard data to prepare us for the long-term effects of type 2 diabetes on patients diagnosed as children, however there are many indications, small studies, and evidence in known pathology of related problems that indicate the Surgeon Generals warning to be accurate. It is known that chronic complication with often fatal results begin within the first one and a half to two decades of onset of diabetes while disability is nearly universal by the third decade. Traditionally patients were diagnosed in their forties at the earliest. As adolescents and children are diagnosed with diabetes, there is a nearly 50% decrease in expected lifespan by these projections.
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