Week 3- Diabetes Flashcards
what is diabetes mellitus
A metabolic disease that involves abnormally elevated blood glucose levels
diabetes mellitus as one of the leading causes of mortality
Reduces lifespan by 5-15 years and the all-cause mortality rate is twice as high as for those without diabetes
what % in US and Canada have diabetes
10-15%
subtypes of diabetes mellitus
type 1 and type 2
maturity-onset diabetes of the young, gestational diabetes, secondary causes due to endocrinopathies/steroid use, etc.
type 1 diabetes- which cells are effected?
Due to the destruction of pancreatic islet beta cells – typically secondary to an autoimmune reaction
age most common to get T1D
4-6 or 10-14 yrs
causes of T1D
One-third of the disease susceptibility is due to genetic factors, with two-thirds attributed to environmental factors
genetic factors for T1D? what’s most common?
HLA
The HLA locus (HLA-DR3, -DR4, -DQ) confers about 40% of the genetic risk to developing Type 1 diabetes, while the 5’ polymorphic region of the insulin gene adds 10%
- Most patients will have circulating antibodies to islet cells, glutamic acid decarboxylase 65, insulin, tyrosine phosphatase IA2, and zinc transporter 8
environmental factors for T1D
less prevalent near the equator
migration?
breastfeeding is protective
hygiene hypothesis- public health and immune system dysregulation and develop autoimmune
what % and who doesnt have the typical pancreatic beta cell autoimmunity in T1D
Approximately 5% of patients have no evidence of pancreatic beta cell autoimmunity = the subgroup of “idiopathic type 1 diabetes” (also known as “type 1B”)
Most of these individuals are of Asian or African descent
symptoms of T1D
Excessive urination (polyuria) and thirst (polydipsia)
Blurred vision
Weight loss
Parasthesias
Altered level of consciousness
is screening recommended for T1D?
no
T2D eitology/ causes
Due to the non-autoimmune loss of pancreatic B cell function or development – leading to impaired insulin sensitivity (“insulin resistance”)
T1D vs T2D cause
T1D: Due to the destruction of pancreatic islet beta cells – typically secondary to an autoimmune reaction
T2D: Due to the non-autoimmune loss of pancreatic B cell function or development – leading to impaired insulin sensitivity (“insulin resistance”)
onset of T2D
adults, but rising in kids
what % is T2D
More than 90% of patients with diabetes in the U.S. have Type 2 diabetes
who has higher prevalence of T2D (race and other risk factors)
Prevalence is 2-6x higher in persons of Black (12.9%), South Asian (14.4%), Arab/west Asian (9.4%), Native American (34.8%), Pima Indian, or Hispanic American (4.5%) backgrounds (Sapra 2023)
Other risk factors include: obesity, first-degree relative with Type 2 diabetes, cardiovascular disease, hypertension, HDL cholesterol <35mg/dL (0.91mmol/L) and/or triglycerides >250mg/dL (2.8mmol/L), acanthosis nigricans, polycystic ovary syndrome, gestational diabetes or delivery of baby >9lb
genetic factors in T2D
Epidemiologic studies looking at monozygotic twins >40 years of age have shown that when Type 2 diabetes develops in one twin, in 70% of cases the second twin will also develop Type 2 diabetes within a year
- Genome studies have identified 143 risk variants and regulator mechanisms for Type 2 diabetes, including loci that code for proteins involved in beta cell function/development (TCF7L2), insulin secretion (e.g., CDKAL1, SLC30A8), fat mass and obesity risk (FTO, MC4R), and insulin resistance (PPARG)
T2D envrioenmtnal factors
visceral obesity –> insulin resistance (subcutaneous fat is less correlated)
metabolic obesity= visceral fat without overt obesity
adipocytes and immune system in T2D
Adipocytes secrete abnormal levels of adipokines (e.g., adiponectin and resistin) that can impair insulin signaling
- The release of TNF-alpha and IL-6 by macrophages and other immune cells activated in adipose tissue can also impair insulin signaling
T2D diagnosis - when do you see symptoms?
Many patients have an insidious onset of hyperglycemia and are initially asymptomatic. Diabetes is recognized only after glycosuria or hyperglycemia is discovered on routine lab testing.
At the time of diagnosis, patients may already have some level of neuropathic or cardiovascular complications
T2D - whos effected?
lower income, not finished university, permanatley unable to work
skin conditions of T2D
Chronic skin conditions:
* Vulvovaginal candidiasis in females
* Balanoposthitis in males
* Acanthosis nigricans
* Eruptive xanthomas
* Lipemia retinalis
other T2D symtpoms
weight, pregnancy complication
Weight gain
* Overweight or obese
* Centripetal fat distribution
* Waist circumference >40 inches for men, >35 inches for women
Obstetrical complications
* Consider Type 2 diabetes in women who have delivered babies over 9 lb (4.1 kg) or have had polyhydramnios, preeclampsia, or unexplained fetal losses