Diabetes Flashcards
What is Diabetes mellitus
group of disorders compromising abnormalities of metabolism (fat, protein and carbohydrate), characterized by hyperglycemia resulting from insulin deficiency or resistance (prevalence for both is increasing)
Signs of Type I diabetes (insulin dependent)
weight loss, polyuria, polydypsia, ketosis (keto-acidotic coma)
Type II diabetes (non-insulin dependent)
often asymptomatic, overweight, infections (urinary tract, vulva), thirst, rarely coma
Complications of Diabetes
blindness, kidney damage, CVD and lower limb amputations -> people can lower occurrence of these by controlling glucose, blood pressure and blood lipid
Incidence of diabetes
higher frequency in Pima Indians and other Native Americans, blacks and Hispanics, lower frequency in whites
Etiology of Type I diabetes
T cell mediated autoimmune disease -> genetic factors (HLA linked) account for 40% of risk (low penetrance), environmental (60% of risk) = viruses (rubella, enterovirus, coxsackievirus, CMV), dietary factors (cow’s milk protein/bovine serum albumin/BSA, early introduction of gluten before 3 months, vitamin D intake protects, breast feeding protects)
Hygiene hypothesis for type I diabetes
environment for young children may be too clean leading to a deficiency in immunoregulation -> low level of expression of gene in heterozygote
Cow’s milk
increase in consumption shows increase in prevalence in countries where consumption is higher -> THEORIES: immature gut mucosa allows antigenic protein to cross (beta casein, beta lactoglobin, albumin -> molecular mimicry of pancreatic beta cell) -OR- bovine insulin in milk may trigger antibodies to insulin *NB: Breastfeeding is protective, DO NOT GIVE COW’S MILK
Type II Diabetes etiology
strong environmental etiology, pathogenesis is defective insulin secretion and action (resistance) -> SECRETORY DEFECT (especially with genetic transmission) -> low birth weight (maternal malnutrition?), chronic hyperglycemia (high glycemic index foods?); PERIPHERAL INSULIN RESISTANCE (impaired insulin-mediated glucose uptake in muscles) -> genetic is 50%, weight gain is 25% and physical inactivity is 25% -> obesogenic environment
Risk factors for type II diabetes
age, family history, ethnic group, social class, fetal nutrition and early growth pattern, diet (SFA), inadequate physical activity, central obesity, metabolic syndrome
Body weight/pattern and type II risk
for each 1kg increase in weight in the population, risk increases by 4.5% -> central adiposity is most important (>1.02 in men and .88 in women have higher insulin levels and are more insulin resistant than patients with similar weight but with peripheral obesity
Central obesity
can result in the metabolic syndrome (most prevalent cause) -> is also a precursor for type II diabetes and atherosclerotic vascular disease -> pattern is more common in men (risk of CVD is same in men and women, but men smoke more, have higher BP/cholesterol and are more likely to have this pattern)
Metabolic syndrome
glucose intolerant, centrally obese (associated with insulin resistance or hyperinsulinemia), HTN, dyslipidemia (increased TAGs or decreased HDL) -> need 3 for diagnosis ->result from failure of the normal actions of insulin -> interrelated with type II diabetes and CVD (increases risk of CHD death and non-fatal MI risk)
Visceral fat
drains directly to the liver via the portal system (peripheral fat does not), more NEFA produced than from gluteal-femoral fat (Non esterified FA delivery to muscle causes insulin resistance), more inflammatory cytokines (causes IR) than from gluteal-femoral fat, adipocytes located here are larger and more resistant to insulin than those in the periphery
Hyperinsulinemia
directly related to waist circumference
