Download Lecture in diabetes mellitus

Dr.Huda Gazi
Diabetes mellitus
Definition:
Is a group of diseases characterized by an elevated blood glucose level
(hyperglycemia) resulting from defects in insulin secretion, in insulin action, or
both.
DM is not a pathogenic entity but a group of etiological different metabolic
defects.
Common symptoms of DM are lethargy from marked hyperglycemia, polyuria,
polydipsia, weight loss, blurred vision and susceptibility to certain infection.
severe hyperglycemia may lead to hyperosmolar syndrome and insulin
deficiency to life-threatening ketoacidosis.
Chronic hyperglycemia causes long-term damage, dysfunction and failures of
various cell, tissues and organs.
Classification of DM:
There were several classification systems established for DM by the WHO
Expert Committee on DM (1980, 1985). The current WHO classification
system has been established in co-operation with the National
Data Group (USA). It is mainly based on the etiology of DM
1.Type 1 DM:
Immune mediated
Idiopathic
2.Type 2 DM
3.Other specific types of DM
Genetic defects of islet B-cell function
Genetic defects of insulin action
Diseases of exocrine pancreas
Endocrinopathies
Drug- or chemical- induced DM
Infections
Other genetic syndromes Uncommon forms of DM
Uncommon forms of DM
4.Gestational DM
Diabetes
Type 1 DM:
is characterized by cellular-mediated autoimmune destruction of islet ß-cells.
Markers:
__ islet cell antibodies (ICAs)
__ auto-antibodies to insulin (IAAs)
__ auto-antibodies to glutamic acid decarboxylase (GAD65)
__ auto-antibodies to tyrosine phosphatases IA-2 and IA-2ß
Association with HLA: DQA and DQB genes:HLA-DR/DQ alleles may be
protective
Environmental factors are poorly defined. Virus infectious and nutritional
factors are discussed.
Age: Onset predominantly in childhood and adolescence, but occurs at any
age
Idiopathic diabetes in African or Asian people. This form of diabetes is
strongly inherited, has
permanent insulinopenia, is prone to ketoacidosis without antibodies to ßcells.
Laboratory findings:
__ Hyperglycaemia
__ Ketonuria
__ Low or undetectable serum insulin and C-peptide levels
__ Auto-antibodies against components of the islet ß-cells
Type 2 diabetes:
(Maturity-onset diabetes, non-insulin dependent diabetes).
Type 2 diabetes is due to insulin insensitivity combined with a failure of insulin
secretion to overcome this by hyper secretion, resulting in relative insulin
deficiency. There is a strong genetic predisposition. Type 2 diabetes is more
common in individuals with family history of the disease, in individuals with
hypertension or dyslipidaemia and in certain ethnic groups.
The risk of developing Type 2 diabetes increases with:
- Family history of diabetes (in particular parents or siblings with diabetes)
- Obesity (≥ 20% over ideal body weight or BMI ≥ 25.0 kg/m²)
- Membership of some ethnic groups
- Age ≥ 45 years
- Previously identified IFG or IGT
- Hypertension (≥ 140/90 mmHg in adults)
- HDL cholesterol level <1.0 mmol/L (<0.38 g/L) and/or a triglyceride level
≥ 2,3 mmol/L (≥2,0 g/L)
- Reduced physical activity
- History of gestational diabetes mellitus (GDM) or delivery of babies >4,5 kg
MODY is a form of youth onset diabetes which is not insulin-dependent, with a
strong dominant family history, and is associated with abnormal hepatic
nuclear factor (HNF) or glucokinase genes.
The characteristic features of Type 1 and Type 2 diabetes are contrasted in
Table1.
Laboratory findings:
__ hyperglycaemia
__ hyperlipidaemia
__ high serum insulin/C-peptide level
__ defective insulin secretion
__ insulin resistance
Gestational diabetes mellitus (GDM):
Definition: Any degree of clinical glucose intolerance with onset or first
recognition during pregnancy.
GDM complicates the pregnancy: The following problems may develop with
GDM:
altered duration of pregnancy
placental failure
hypertension / pre-eclampsia
high birth weight of the newborn
Therapy: nutrition therapy
insulin (glucose-lowering drugs not advised).
Diagnosis of GDM:
Fasting plasma glucose level >7,0 mmol/L (>1,26 g/L) or casual plasma
glucose >11,1 mmol/L (>2,00 g/L), confirmed on a subsequent day.
Laboratory strategy to diagnose GDM:
One step approach: OGTT (75 g glucose)
Two step approach: 1. First OGTT with 50 g glucose load; cut-off value
after1hour plasma glucose >7,8 mmol/L (>1,40 g/L)
2. Second OGTT with 75 g glucose load and evaluation as the standard
OGTT
Six weeks after pregnancy or later the woman should be re-examined for the
presence of diabetes mellitus or IGT.
Prevalence of diabetes:
The prevalence of diabetes in Western life-style countries is estimated to be
between 6,0 and 7,6 %. In some developing countries the prevalence is more
than 6 % (Middle East, Western Pacific). The mean percentage prevalence
varies between ethnic groups (American Indians,Hispanics, and others).
Between 1995 and 2025 there is predicted to be a 35 % increase in the
world-wide prevalence of diabetes. The rising number of people with diabetes
will occur mainly in populations of developing countries, leading to more than
300 million people with diabetes globally by 2025. Presently as many as 50 %
of people with diabetes are undiagnosed. Since therapeutic intervention can
reduce complications of the disease, there is a need to detect diabetes early
in its course. The risk of developing Type 2 diabetes increases with age,
obesity,and lack of physical activity.
Clinical evaluation of diabetes:
History

Symptoms of diabetes (urination, thirst, weight loss, vision change)

Current medications

Past medical history

Family history (focus on diabetes, heart and vascular problems, kidney
failure)

Evidence of current diabetic complications (vision loss, edema, vascular
problems in feet, foot ulcers, paresthesias)

Other risk factors (smoking, alcohol abuse, drug abuse, obesity, history of
cholesterol elevation or hypertension, family history of diabetes)

Life style factors (occupation, level of daily exercise, eating patterns,
economic level)

Dietary history
Physical Examination

Height and weight (calculate BMI)

Blood pressure

Ophthalmoscopic exam (visual acuity, fundoscopic exam – refer to
ophthalmologist for complete exam)

Mouth and dental condition

Thyroid abnormalities

Cardiac exam

Abdominal exam

Peripheral pulses and distal capillary circulation

Skin condition and edema, especially legs

Neurological exam (especially distal tendon reflexes, foot pin, vibration,
position, temperature sensation)

Condition of feet and toes
Initial Laboratory Evaluation

Fasting plasma glucose

Hemoglobin A1C

Fasting cholesterol, LDL, HDL, Triglycerides

Creatinine

Urine albumin, ketones, and glucose (dipstick)

Single urine specimen for quantitative albumin – may calculate
Albumin/Creatinine ratio (or 24 hr. urine for albumin and creatinine
clearance)

ECG in adults
Referral
Consider initial referral to the following if significant disease is found:

Ophthalmology – if retinal disease is seen or suspected

Nephrology – if initial serum creatinine is >1.5

Neurolgy – if peripheral neuropathy is noted

Emergency Dept. – if severe hyperglycemia is noted (>400)
Additional risk factors that increase the morbidity and mortality of
diabetes:

Hypertension

Smoking

Hyperlipidemia

Age: Prevalence and risks increases with age

Obesity and age >40 years

Hx of gestational diabetes or delivery of large babies > 4kg.

Alcohol or drug abuse
Management of chronic diabetes, Type II:
Review correct measurement of blood glucose:

Timing of measurement
o Ideal measurement – after fasting for 8-10 hours
o 2 – 4 hours postprandial may give some information on effectiveness of
antiglycemic medication

Encourage patients to consider purchasing their own glucometer and
strips for self-monitoring. Teach patients correct use of machine and
recording of results. Advantages include:
o Greater awareness of relationship between activity, exercise, diet,
and medication
o Greater collaboration in management of disease
o Improved communication with health care providers
Initial management of chronic diabetes Type II

Goals of management
o Maintain fasting plasma glucose of 90-130 mg/dl.
o Blood pressure < 130/80
o LDL cholesterol < 100 mg/dl.

Initial trial of diet
o Calorie restricted to 1600 – 1800 calories; 50-60% starchy
carbohydrates, 20% fats, 20% protein
o Add daily fiber in form of beans, oats or other whole grains, or fiber
product such as psyllium seed (Metamucil) – 8-10 gms/day
o Main goal of diet is gradual weight loss in obese patients to increase
insulin sensitivity and increased fiber to stabilize glucose absorption

Regular exercise program – daily for 30 minutes continuously

Monitor and treat blood pressure if > 130/80

Monitor and treat LDL cholesterol if > 100 mg/dl.

Evaluate emotional adjustment to diagnosis and management goals;
counsel as needed

If diet, exercise, and weight loss does not achieve goal glucose levels with
2-4 months, begin medication:
o Step 1: glibenclamide – begin at 2.5 mg/day, increase as needed to 20
mg/day
o If no response to above:
Step 2: Add metformin – begin at 500 mg/day, increase as needed to
2500 mg/day in two equally divided doses
o If no response to above:
Step 3: Begin insulin therapy, usually by discontinuing oral medications
– consider referral for initiation of insulin therapy

IF patient significantly obese (BMI > 30):
o Step 1: May BEGIN with metformin 500 mg/day, increase as needed to
2500 mg/day in two equally divided doses
o If no reponse to this:
Step 2: Add glibenclamide - begin at 2.5 mg/day, increase as needed
to 20 mg/day.
Maintenance management of chronic diabetes type II

Follow flow sheet protocol for visits, usually monthly until well stabilized

Goals of diabetes management – NOTE that goals for chronic diabetes
may be somewhat different for good control, not ideal goals which are
normal for a non-diabetic)
Intervention
Ideal (normal)
Acceptable
Fasting blood sugar
<125
< 140
HbA1C
<6
<7
Blood pressure
<130/80
<140/90
Serum total cholesterol
<200
< 240
LDL cholesterol
<100
<130
Stop smoking
No smoking
No smoking
Decrease weight
BMI <25
BMI < 30
Daily Exercise
Daily 30-60
Daily 30 min.
min.

Monthly:
o Blood pressure
o Weight
o Fasting glucose
o Urine albumin
o Foot exam for lacerations, superficial infections, ulcerations, etc.
o Neurologic exam (especially lower extremities – temperature, vibration,
or position sensation, pin prick sensation)
o Medication dose review
o Patient education – may rotate topics discussed
o Monitor for stress, anxiety, and depression
Every 3 months:
o Hemoglobin A1C
o Quantitative albumin/creatinine ratio (requst single urine specimen for
quantitative albumin, and request serum creatinine)

Albumin/creatinine ratio calculated by dividing urine albumin (in
mg/l by serum creatinine (in mg/100 ml.) Result is an empiric
ratio that correlates with presence or absence of early
nephropathy (normal <30, suspected nephropathy >30)

Refer to specialist if Alb/Creat ratio >30 for followup. May
consider starting daily dose of captopril or enalapril to preserve
renal function, even if blood pressure normal or mildly elevated

Every year (especially after 10 years duration of diabetes or age >40)
o Refer to ophthalmologist for fundoscopic evaluation
o Monitor serum cholesterol, HDL, LDL, Creatinine
o ECG in adults > 40 years
Management of special diabetic populations:
1.Hypertension
-Control BP with lifestyle changes and medications as needed
-Goal <130/80 (new guidelines)
2.Elderly Show increased sensitivity to anti-diabetic medication; reduce
initial dosage by 50%
3.Renal disease Follow serum creatinine and Alb/Creat ratio regularly;
consider adding an ACE inhibitor in consultation with nephrologist
4.Pregnancy: Refer to Ob/Gyn for management during pregnancy
5.Coexisting heart or vascular disease Refer to cardiologist for comanagement
Prevention issues & health education messages:

Screening for diabetes
o Consider screening all adults over 40 years of age with fasting blood
sugar every 2-3 years
o Begin screening at earlier age with a positive family history, obesity, or
symptoms of diabetes
o Involve the community in diabetes awareness and screening

Nutrition – Encourage low saturated fat, high fiber diet

Smoking cessation

Obesity – encourage weight loss to keep BMI < 30
Daily Aspirin – ½ tablet (160) mg can reduce risk of stroke or myocardial
infarction; small risk of bleeding complications especially in the elderly.