Nutrition and Medicine, 2006 Tufts University School of Medicine Nutrition and Type 2 Diabetes: Learning Objectives
Margo N Woods, DSc
1 Discuss the increase in the incidence and prevalence of type 2 diabetes in the population and the shift in age of onset 2 List the criteria used to identify a person with type 2 diabetes 3 List the five criteria used to define Metabolic Syndrome 3 out of the 5 are needed for diagnosis 4 Identify the nutritional factors that have been associated with t2DM and the Metabolic Syndrome and which have been identified as causal factors 5 Discuss the relative effect of obesity BMI vs quality of dietary intake on t2DM and Metabolic Syndrome 6 Identify the steps of lifestyle intervention diet and exercise that can be used in a clinical setting to prevent/treat type 2 diabetes
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Nutrition and Type 2 Diabetes: Answers to the Learning Objectives
After this lecture the students will be able to: 1 Discuss the increase in the incidence and prevalence of type 2 diabetes in the population and the shift in age of onset Diabetes is one of the most common diseases in the US It is estimated that 167 million US adults about 8 of the total adult US population have
diagnosed diabetes If undiagnosed diabetes is included, it is estimated that more than 1 in 10 adults in the US has diabetes Over 93 of patients with diabetes have type 2 Other epidemiologic figures of interest include: About 1 million new cases are diagnosed annually The prevalence of diagnosed diabetes increased 61 from 1990 to 2001 mostly due to the aging of the population and the increase in the prevalence of obesity the major risk factor for type 2 diabetes, but also due to increased awareness The estimated lifetime risk of developing diabetes if born in 2000 is 35, while a Hispanic female born in 2000 has a 50 chance of developing diabetes In addition to those with diagnosed or undiagnosed diabetes, close to 15 million people have glucose intolerance, which is considered a pre-diabetic state
Diabetes discriminates It afflicts those who can afford it the least older [1 out of 5 individuals over 65 has diabetes], ethnic minorities [Hispanics, Non-Hispanic blacks and AsianAmericans], those in low socioeconomic status Overweight/obesity is the major risk factor for t2DM Given the increase in the prevalence of overweight/obesity in the population, t2DM is now seen more in
children and adolescents Diabetes is a serious disease People with diabetes and its associated Metabolic Syndrome see below have an increased risk for macrovascular complications stroke, ischemic heart disease, peripheral vascular disease and microvascular complications retinopathy, nephropathy and neuropathy Diabetes is the leading cause of blindness, chronic kidney disease and non-traumatic limb amputation in the US Compared to people without diabetes, persons with diabetes are 2 to 4 times more likely to develop cardiovascular disease heart disease, peripheral disease, stroke Diabetes during pregnancy is a principal cause of congenital malformations, perinatal mortality and premature mortality
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2 List the criteria used to identify a person with type 2 diabetes Diabetes is a dysmetabolic disorder affecting multiple bodily functions The diagnosis of diabetes is based on the presence of hyperglycemia, as shown below
Diagnosis of Diabetes Mellitus
Glucose Intolerance: Diabetes: Classic symptoms of diabetes PLUS casual plasma glucose 200 mg/dL or Morning FPG 126 mg/dL or 2-hour PG 200 mg/dL
100 Morning FPG 126 mg/dL IFG 140 2-hour PG 200 mg/dL IGT
Unless unequivocal
hyperglycemia with metabolic decompensation is present, a diagnosis of diabetes must be confirmed by repeating any of the tests on a different day IFG impaired fasting glucose, IGT impaired glucose tolerance Classic symptoms of diabetes include: polyuria, polydipsia, and unexplained weight loss Casual is defined as any time of the day without regard to time since last meal FPG fasting plasma glucose, defined as no consumption of food or beverage other than water for at least 8 hours 2-hour PG 2 hour post load glucose during a 75-gram oral glucose tolerance test
Glucose intolerance, denoted by Impaired Fasting Glucose IFG or Impaired Glucose Tolerance IGT, is not a clinical entity on its own but rather an independent risk factor for progression to clinical diabetes and development of macrovascular complications Once diabetes is diagnosed as shown above, then the type of diabetes needs to be defined, based on etiology There are several types of diabetes to be discussed in detail during 2nd year, the most common ones are type 1 and type 2 The terms insulin dependent diabetes mellitus and non-insulin-dependent diabetes mellitus and their acronyms, IDDM and NIDDM, have been
eliminated These terms had been confusing and had frequently resulted in classifying the patient based on treatment rather than etiology Type 1 is due to autoimmune pancreatic beta cell destruction leading to insulin deficiency and is generally seen in young, thin persons Type 2 is due to a combination of insulin resistance impairment in the action of insulin and relative insulin deficiency, and is generally seen in older, overweight/obese persons
3 List the 5 criteria used to define Metabolic Syndrome 3 out of the 5 are needed for diagnosis In addition to hyperglycemia, t2DM is thought to be related to a cluster of metabolic abnormalities such as central obesity, hypertension, dyslipidemia and increased risk for cardiovascular disease, collectively known as the Metabolic Syndrome Recently, specific criteria for the metabolic syndrome were defined, as shown below: Adult Treatment Panel III Diagnostic Criteria for the Metabolic Syndrome
Metabolic Syndrome is defined as having three or more of the following: Abdominal Obesity Waist circumference 102 cm in men and 88 cm in women
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Hypertriglyceridemia Low HDL Hypertension High Fasting Glucose
150 mg/dL 40 mg/dL in men and 50
mg/dL in women 130/85 mmHg 110 mg/dL
4 Identify the nutritional factors that have been associated with t2DM and the Metabolic Syndrome and which have been identified as causal factors There are several epidemiologic studies that have identified certain nutritional factors that have been associated with development of t2DM and the Metabolic Syndrome Causality is suggested by observational prospective studies, but can only be confirmed in randomized trials The evidence is summarized in the table below TABLE 1 Summary of the Evidence for Potential Nutritional Interventions for Prevention or Delay of Type 2 Diabetes
Intervention Cohort WEIGHT LOSS Risk Source of Evidence Randomized controlled trials risk Metaanalyses Recommendation for Prevention of Type 2 Diabetes
Weight loss of 7 of initial weight will decrease diabetes risk by 58 over 3 years Decrease which leads to weight loss
MACRONUTRIENTS Fat Monounsaturated Polyunsaturated Saturated Trans Fatty Acids Nuts and Peanut Butter Carbohydrate Glycemic Index Cereal Fiber/Whole Grain Protein OTHER Alcohol
or risk or risk or risk or risk or risk risk or risk risk risk risk risk
Decreased consumption risk
Decreased consumption risk Decreased consumption risk risk or insulin sensitivity
Increase for CHD protection Increase for CHD protection Decrease for CHD protection Decrease for CHD protection Insufficient evidence Probably no role Probably a role but insufficient evidence Probably a role
Probably no role For those who desire to drink: 2 drinks/day for men 1 drink/day for women Type of drink not important Insufficient evidence Insufficient evidence One multivitamin daily especially in people
Dairy/Calcium Caffeine MICRONUTRIENTS Multivitamin
risk or risk risk
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Antioxidants Vitamin C Vitamin E Selenium Carotenoids -carotene Chromium Magnesium Vitamin D
risk
risk
with poor dietary habits Probably no role
or risk risk risk
risk
Probably no role Probably in deficient people but insufficient evidence Insufficient evidence
As a component of a multicomponent nutritional intervention in the Finish Diabetes Prevention Study As the main component of the nutritional intervention in the Diabetes Prevention ProgramCHD coronary heart disease
5 Discuss the relative effect of obesity BMI vs quality of dietary intake on t2DM and
Metabolic Syndrome Perhaps the most significant modifiable risk factor for the development of t2DM and the MS is obesity The increase in the prevalence of diabetes in the United States during the last two decades is paralleled by an increase in the prevalence of obesity However, only a minority of overweight individuals develop clinical diabetes There are at least two potential explanations for this observation The first is that distribution of adipose tissue may be more important than overall weight, with visceral depots contributing more to insulin resistance The second explanation is that the secretory capacity of the beta islet cell differs between individuals, leading to relative insulin deficiency in the setting of increased insulin requirements in predisposed individuals Given the pivotal role of obesity in the development of type 2 diabetes, interventions that result in weight loss are the most effective means in decreasing diabetes risk This is highlighted by two recently completed large clinical trials for prevention of type 2 diabetes, which are compared in the table shown in the next page Which method/approach is the most effective one to achieve and maintain weight
loss is highly controversial, as discussed elsewhere in this course Beyond a reduction in BMI, there is significant evidence to suggest that the quality of the diet may play a role in decreasing risk of t2DM as described in TABLE 1 These nutritional interventions and details regarding their potential mechanism of action will be discussed in class and are also summarized in the required reading TABLE 2 Randomized Controlled Trials for Prevention or Delay of Type 2 Diabetes and/or the Metabolic Syndrome
Mean Incidence of
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Number of Subjects Study Finnish Diabetes Prevention Study DPS Diabetes Prevention Program DPP Intervention Intensive Lifestyle Modifications Control Lifestyle Modifications Metformin 850 mg twice daily Control 265 257 1079 1073
Duration of Followup years 32
Diabetes per 100 personyears 32 78
Relative Risk Reduction 58
NNT 22 over 1 year 5 over 5 years
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48 78
58 31
16 over 1 year 7 over 3 years 31 over 1 year 14 over 3 years
1082
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In the incidence of clinical diabetes diagnosed by fasting plasma glucose or oral glucose tolerance test at the end of the trial compared with control or placebo
NNT the number of patients needed to treat over a
period of time to prevent one adverse outcome
DPS Lifestyle Modification: weight reduction of 5 or more, fat intake 30 of total energy, saturated fat intake 10 of total energy, fiber intake 15 g/1000 kcal, frequent ingestion of whole grain, vegetables, fruits, low-fat milk and meat, soft margarine and vegetable oils rich in monounsaturated fatty acids, and moderate exercise 30 minutes/day
DPP Lifestyle Modification: weight reduction of 7 or more with low-fat diet and moderate physical activity of equal to or more than 150 minutes/week Interventions achieved through multiple individualized and group sessions
6 Identify the steps of lifestyle intervention diet and exercise that can be used in a clinical setting to prevent/treat Type 2 Diabetes Case: A 53-year old man with a family history of t2DM who has been gaining weight steadily over the last two decades was found to have a fasting plasma glucose of 101 by his primary care physician He is a busy executive of a start-up company with three young children and a spouse who is a cardiothoracic surgeon He drinks plenty of coffee every day and is worried about adverse effects He stopped drinking alcohol last year because he is
concerned about adverse effects On exam, his BMI is 295 and his BP is 144/86 He is very concerned about his developing t2DM does not want to be like his father who had both of his legs amputated and died of a heart attack at the age of 74 He is willing to try hard with nonmedication interventions What do you advice? This is a patient with significant risk factors for progression to t2DM, who is motivated to change but also has a busy lifestyle which limits his opportunities for major lifestyle changes The focus here is to adapt what you know about t2DM prevention to his lifestyle He has the luxury of adequate income but not time First, one needs to get exact information about current activity and nutrition before advice After reviewing what he does, one focuses on what he can improve A reasonable lifestyle regimen would be as follows:
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At all cost, maintain current weight and, if possible, lose 5 of weight If possible, formal exercise 1 hr 2-3 x /week, 30 mins aerobic, 30 mins weight training Incorporate exercise during the day eg take stairs, avoid driving, play sports with children, etc Never skip a meal Follow the DASH diet o Increase intake of vegetables and
fruits to 5-6 cups/portions per day o Choose only lean meats, chicken and fish at 2 servings a day a serving is 3 oz which is the size of a deck of cards All dairy products should be reduced in fat, have 2-3 servings a day o Choose a serving of beans 1/2 cup or nuts 1/4 cup each day Always have healthy eg whole grain, fruit snacks available Substitute refined carbohydrates with whole grains If socially acceptable, share your meal when eating out Drink nothing other than water, and, if desired, 1-2 glasses of skim milk/day No need to decrease coffee in relation to t2DM prevention No need to eliminate alcohol 2-3 drinks per day is beneficial in terms of t2DM Take a multivitamin Check vitamin D level and supplement as needed
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