dr abdullah alshaya pediatric endocrinologist
DESCRIPTION
Introduction Insulin regimen Insulin dose Diet Monitoring Hypoglycemia Management during infection Screening for chronic complicationTRANSCRIPT
Type I DM in Type I DM in PediatricPediatric
Dr Abdullah AlshayaPediatric Endocrinologist
• Introduction• Insulin regimen• Insulin dose• Diet• Monitoring• Hypoglycemia• Management during infection• Screening for chronic complication
DIAGNOSTIC CRITERIA FOR IMPAIRED GLUCOSE TOLERANCE AND DIABETES
MELLITUS
Diagnostic Criteria of Impaired Glucose Tolerance and Diabetes Mellitus Table
Symptoms include polyuria, polydipsia, and unexplained weight loss with glucosuria and ketonuria. A fasting glucose concentration of 99 mg/dL is the upper limit of “normal”.
Etiologic Classification of Diabetes Mellitus Table
Classification of DiabetesType I DMType I DM Type II DMType II DM
Aetiology Autoimmune (- cell destruction)
Insulin resistance and -cell dysfunction
Peak age 12 years 60 years
Prevalence 0.3% 6% (>10% above 60 years)
Presentation Osmotic symptoms, weight loss (days to weeks), DKAPatient usually slim
Osmotic symptoms, diabetic complications (months to years).Patient usually obese
Treatment Diet and insulin Diet, exercise (weight loss), oral hypoglycemics, Insulin later
Epidemiology:
The incidence among school-age children is about 1.9/ 1,000 in USA with annual incidence about 14.9 new cases/ 100,000 children.
• Sex: M:F ratio is 1:1.• Age at presentation: Peaks occur in 2 age
groups. At 5-7 yr of age and puberty
• Seasonal variations: More frequent in the autumn and winter months.
Etiology:
The Mechanisms that lead to failure of
pancreatic ß-cell function increasingly point
to an auto immune destruction ofpancreatic islet ß cells in
predisposed individuals.
Evidences supporting the auto immune basis of type 1 DM (T1DM)
1. Type 1 DM is commonly associated with auto immune diseases as celiac disease, Addison disease, and thyroiditis.
2. Auto antibodies as (GAD)and islet cell cytoplasm antibodies (ICA) and insulin auto antibodies (IAA) are detected in the sera of newly diagnosed patients.
Evidences supporting the auto immune basis of type 1 DM (T1DM)
3. Genetic predisposition (the increased protection and susceptibility to T1DM)
The Genetics of type 1 DM cannot be classified according to a specific model of inheritances. The most important genes are located within the MHC HLA class II region on chromosome 6p21, accounting for about 60% of genetic susceptibility for the disease.
Evidences supporting the auto immune basis of type 1 DM (T1DM)
4. EnvironmentFactors such as viral infections, chemicals, seasonal factors, and dietary factors have been suspected of contributing to differences in the incidence and prevalence of type 1 DM in various ethnic populations.
Evidences supporting the auto immune basis of type 1 DM (T1DM)
a. Viral Infections: A variety of viruses and mechanisms may contribute to the development of T1DM in genetically susceptible hosts. Enteroviral, congenital rubella, and mumps infection leads to the development of ß-cell auto immunity with high frequency and to T1DM in some cases. Congenital rubella infection is associated with diabetes (up to 40%).
Evidences supporting the auto immune basis of type 1 DM (T1DM)
b. Diet
• Breast-feedingMay lower the risk of T1DM, either directly or by delaying exposure to cow’s milk protein.
Evidences supporting the auto immune basis of type 1 DM (T1DM)
• Early introduction of cow’s milk protein and early exposure to gluten in cereals have both been implicated in the development of auto immunity and it has been suggested that this is due to the “leakiness” of the immature gut to protein antigen
• s. Antigens that have been implicated include ß-lactoglobulin, which is homologous to the human protein glycodelin (PP14), a T-cell modulator. Other studies have focused on bovine serum abumin as the inciting antigen,.
Evidences supporting the auto immune basis of type 1 DM (T1DM)
• Other dietary factors that have been suggested at various times as playing a role in diabetes risk include Omega-3 fatty acids, Vitamin D, ascorbic acid, zinc, and Vitamin E
• Vitamin D has a role in immune regulation, decreased Vitamin D levels in pregnancy or early childhood may be associated with diabetes risk; but the evidence is not yet conclusive.
Evidences supporting the auto immune basis of type 1 DM (T1DM)
c. Psychologic stress: Several studies show an increased prevalence of stressful psychologic situations among children who subsequently developed T1DM. Whether these stresses only aggravate pre-existing auto immunity or whether they can actually trigger auto immunity remains unknown.
Pathogenesis and natural history of type 1 diabetes mellitus
A genetically susceptible host develops auto immunity against his or her own ß cells. What triggers this auto immune response remains unclear at this time. In some ( But not all) patients, this auto immune process results in progressive destruction of ß cells until a critical mass of ß cells are destroyed and the patient becomes totally dependent on exogenous insulin for survival.
Pathogenesis and natural history of type 1 diabetes mellitus
1.Initiation of auto immunity.2. Preclinical auto immunity with progressive loss of ß-cell function.3. Onset of clinical disease.4. Transient remission (honeymoon period).5. Established disease.6. Development of complications.
Pathophysiology
In normal individuals, there are normal swings between the postprandial, high-insulin anabolic state and fasted, low-insulin catabolic state that affect 3 major tissues: liver, muscle, and adipose tissue.
Influence of feeding (High Insulin) or of fasting (Low Insulin) on some Metabolic processes in liver, muscles and adipose tissue.
Tissue Postprandial State(High Plasma
Insulin)
Fasted State(Low Plasma
Insulin)Liver • Glucose uptake,
glycogen synthesis, absence of gluconeogenesis• Lipogenesis• Absence of ketogenesis
• Glucose production (glycogenolysis + gluconeogenesis)• Absence of lipogenesis• Ketogenesis
Muscle • Glucose uptake and oxidation, and glycogen synthesis• Protein synthesis
• Absence of glucose uptake• Glycogenolysis•Proteolysis and amino acid release
Adipose Tissue
• Glucose uptake• Triglyceride uptake• Lipid synthesis
• Absence of glucose uptake•Absence of triglyceride uptake• Lipolysis and fatty acids release
1. Hyperglycemia- (fasting and increases after eating): due to glucose production (glycogenolysis and gluconeogenesis) and absence of glucose uptake by muscle and adipose tissues.
2. Glucosuria - When blood glucose level exceeds the renal tubular maximum (Tm) of glucose (180 mg/dL). Calories are lost in urine a compensatory hyperphagia. If the Hyperphagia does not keep pace with the glucosuria, loss of body fat ensues with clinicalweight loss.
Influence of feeding (High Insulin) or of fasting (Low Insulin) on some Metabolic processes in liver, muscles and adipose tissue.
3. Metabolic Acidosis- Insulinopenia, diminished energy production from glucose lipolysis. Peripheral utilization of fatty acids is incomplete and they are converted to ketone bodies in the liver. Accumulation of ketoacids (acetoacetic, ß-hydroxybutyric acids) will lead to metabolic acedosis. Ketoacidosis leads Kussmaul respiration (deep rapid breathing), fruity breath odor (acetone), diminished neurocognitive function, and possible coma.
4. Dehydration and loss of electrolytes Ketones in association with cations are excreted in urine- loss of fluid and electrolytes, also hyperglycemia will lead to osmotic diuresis.
5. Hyperosmolality - It is due to dehydration and hyperglycemia.Serum osmolality in mOsm/kg=2 (serum Na) glucose mg/ dL /18 + BUN mg/ dL /3.
• 6. Impaired level of consciousness- it is due to dehydration, hyperosmolality, metabolic acidosis, and diminished cerebral oxygen utilization.
Clinical Manifestations
Different clinical presentations
1. The classic presentation of diabetes in children is a history of polyuria, polydipsia, hyperphagia, and loss of weight (loss of body fat). The duration of these symptoms is often less than 1 mo. Hyperphagia occurs as a compensatory mechanism when calories are lost in the urine (glucosuria).
Clinical Manifestations
2. Enuresis (due to polyuria) in a previously
toilet-trained child.
3. Insidious onset with lethargy, weakness,
and weight loss (in spite of an increased Apetite).
4. Pyogenic skin infections or monolial vaginitis ( in teenage girls due to chronic glucosuria).
Clinical Manifestations
5. Diabetic ketoacido sis- it is the clinical presentation of 20%-40% of new-onset diabetic children and in children with known diabetes who omit insulin doses or who do not successfully manage the precipitating factors (trauma, infection, vomiting, and psychologic disturbances).
Clinical Manifestations
• The early manifestations may be mild (nausea, vomiting, polyuria and dehydration).
• Kussmaul respiration (deep rapid respiration due to metabolic acidosis in an attempt to excrete excess CO2) with an odor of acetone on the breath (acetone is formed by non enzymatic conversion of acetoacetate).
Clinical Manifestations
• Abdominal pain or rigidity (DD: appendicitis, pancreatitis), nausea, and emesis.
• Severe dehydration • Cerebral obtundation and ultimately
coma.
Diagnosis of T1DM
1. Hyperglycemia- Non fasting blood glucose value exceeding 200 mg/ dL with typical symptoms.
2. Glucosuria
DDThe differential diagnosis of diabetes mellitus is not difficult, since this is virtually the only condition that gives rise to hyperglycemia, glucosuria and ketosis.
. Renal glucosuria
Isolated Congenital disorder.
Renal tubular disorder (Fanconi syndrome, Renal disorders due to intoxication by heavy metals {lead} or outdated tetracycline or inborn errors of metabolism {cystinosis}).
DD
. Causes of metabolic acidosis
Uremia, gastroenteritis with metabolic acidosis, hypoglycemia, lactic acidosis, salicylate intoxication, sepsis and encephalitis.
. Physical stress
Transient hyperglycemia with glucosuria, this is induced by counter regulatory hormones.
New-Onset Diabetes without Ketoacidosis
• Excellent diabetes control involves many goals• to maintain a balance between tight glucose control
and avoiding hypoglycemia• to eliminate polyuria and nocturia, to prevent
ketoacidosis• permit normal growth and development with minimal
effect on lifestyle.
initiation and adjustment of insulin,• extensive teaching of the child and caretakers• reestablishment of the life routines.
• Each aspect should be addressed early in the overall care.
• therapy can begin in the outpatient setting, with complete team staffing by a pediatric endocrinologist, experienced nursing staff, dietitians with training as diabetes educators, and a social worker.
• Close contact between the diabetes team and family
must be assured. Otherwise, initial therapy should be
done in the hospital setting.
Types of InsulinTypes of Insulin• Rapid Acting:
– Insulin lispro (Humalog) ®
– Insulin aspart (Novolog) ®
– Insulin glulisine (Apidra) ®
• Short-acting:
– Regular
• Intermediate-acting:
– NPH
• Long-acting:
– Insulin glargine (Lantus) ®
– Insulin detemir (Levemir) ®
– Insulin degludec (tresiba)
Rapid (lispro, aspart, glulisine)
Hours
Long (glargine)
Short (regular)
Intermediate (NPH)
Long (detemir)
InsulinLevel
0 2 4 6 8 10 12 14 16 18 20 22 24
Pharmacokinetics of Insulin ProductsPharmacokinetics of Insulin Products
Adapted from Hirsch I. N Engl J Med. 2005;352:174-183.
Normal Insulin SecretionNormal Insulin Secretion
Basal (background) insulin needs0
10
20
30
40
50
0 2 4 6 8 10 12 14 16 18 20 22 24
Seru
m in
sulin
(µU
/mL)
Time
Meal Meal Meal Bolus (meal) insulin needs
60
Common Insulin Regimens• The goal of treatment in type 1 DM is to provide
insulin in as physiologic a manner as possible.• Insulin replacement is accomplished by giving a basal
insulin and a preprandial (premeal) insulin• The basal insulin is either long-acting (glargine or
detemir • The preprandial insulin is either rapid-acting (lispro,
aspart, or glulisine) or short-acting (regular)
• For patients on intensive insulin regimens (multiple daily
injections or insulin pumps), the preprandial dose is based on the
carbohydrate content of the meal (the carbohydrate ratio)
• plus a correction dose if their blood glucose level is elevated
• This method allows patients more flexibility in caloric intake and
activity, but it requires more blood glucose monitoring and
closer attention to the control of their diabetes.
4:00 16:00 20:00 24:00 4:00
Breakfast Lunch Dinner
8:0012:008:00
Glargine or detemir
Plas
ma
insu
linBasal/Bolus Treatment Program With Rapid-
Acting and Long-Acting Analogs
Bed
Rapid (lispro, aspart, glulisine)
Rapid (lispro, aspart, glulisine)
Rapid (lispro, aspart, glulisine)
Subcutaneous Insulin Dosing
Age (years)
0-5
5-12
12-18
Target Glucose (mg/dL)
100-200
80-150
80-130
Target Daily Insulin (units/kg/d)
0.6-0.7
0.7-1.0
1.0-1.2
Basal Insulin (% of total daily dose)
25-30
40-50
40-50
Bolus Units added per 100 mg/dL above target
Insulin Units Added per 15 g at Meal
0.5 0.5
0.75 0.75
1.0-2.0 1.0-2.0
Newly diagnosed children in the “honeymoon” may only
need 60-70% of a full replacement dose. Total daily dose
per kg increases with puberty.
Newly diagnosed children who do not use carbohydrate
dosing should divide the nonbasal portion of the daily
insulin dose into equal doses for each meal
Indeed, bolus-basal treatment with multiple injections is better adapted to the physiologic profiles of insulin and glucose and can therefore provide better glycemic control than the conventional two-to-three dose regimen. This approach allows insulin doses to be changed as needed to correct hyperglycemia, supplement for additional anticipated carbohydrate intake, or subtract for exercise.
Some families may be unable to administer four daily injections. In these cases, a compromise may be needed:
A three-injection regimen: Combining NPH with a rapid analog bolus at breakfast, a rapid acting analog bolus at supper, and NPH at bed time. This regimen may provide fair glucose control.
A two-injection regimen: This would require NPH combined with a rapid analog bolus at breakfast and supper. However, such a schedule would provide poor coverage for lunch and early morning, and would increase the risk of hypo glycemia at midmorning and early night.
a. The total daily insulin requirement is calculated.
b. 2/3 of the daily dose is given before breakfast and 1/3
before supper (if the total dose is 30 U, 20 U will be given
before breakfast and 10 U before supper).
c. Each injection consists of intermediate and regular insulins
in proportions of 2: 1 or 3:1 (20 U before breakfast =14U of
NPH + 6 U of regular insulin, and 10 U before supper= 6 U of
NPH + 4 U of regular insulin).
Fine Adjustment of the Two Injection Fine Adjustment of the Two Injection RegimenRegimen
INSULIN DOSAGEINSULIN DOSAGEInsulin requirement is based upon the body weight, age, and pubertal stage of the child
In general, the newly diagnosed child requires an initial total daily insulin dose of 0.5 to 1.0 units/kg.
Prepubertal children usually require lower doses, and the dose requirement may be as low as 0.25 units/kg for a variable period following diagnosis.
Higher doses are needed in pubertal children, patients in ketoacidosis, or in patients receiving glucocorticoid therapy.
INSULIN DOSAGEINSULIN DOSAGEIn infants and toddlers who receive their insulin by syringe, the insulin dose may be so small that dilution is required to allow for easier and more precise administration.
The smallest dose of insulin that can be accurately administered without dilution using a syringe is 0.5 units.
Many insulins can be diluted either at a specialized pharmacy or at home with proper training.
Specific diluent for many insulin preparations is available from the insulin manufacturer.
Some insulin pumps can deliver much smaller doses of insulin, of the order of 0.025 units at a time, often obviating this problem.
INSULIN DOSAGEINSULIN DOSAGE
On average, 1 unit of insulin is required to cover:
•20 grams of carbohydrates in most young children (1 to 6 years of age)
•10 to 12 grams of carbohydrates in older prepubertal children
•8 to 10 grams in pubertal adolescents
Hypoglycemic Reactions Hypoglycemic Reactions • Hypoglycemia is the major limitation to tight control of glucose levels. Once
injected, insulin absorption and action are independent of the glucose level,
thus creating a unique risk of hypoglycemia from an unbalanced insulin
effect. Insulin analogs may help reduce but cannot eliminate this risk.
• Most children with T1DM can expect mild hypoglycemia each week,
moderate hypoglycemia a few times each year, and severe hypoglycemia
every few years. These episodes are usually not predictable,
• although exercise, delayed meals or snacks, and wide swings in glucose
levels increase the risk.
Infants and toddlers are at higher risk because they have more variable
meals and activity levels, are unable to recognize early signs of
hypoglycemia, and are limited in their ability to seek a source of oral
glucose to reverse the hypoglycemia.
The very young have an increased risk of permanently reduced cognitive
function as a long-term sequela of severe hypoglycemia. For this reason, a
more relaxed degree of glucose control is necessary until the child
matures
Hypoglycemia can occur at any time of day or night.
Early symptoms and signs (mild hypoglycemia) may occur with a suddendecrease in blood glucose to levels that do not meet standard criteriaFor hypoglycemia in nondiabetic children.
The child may show pallor, sweating, apprehension or fussiness, hunger, tremor, and tachycardia, all due to the surge in catecholamines as thebody attempts to counter the excessive insulin effect. Behavioralchanges such as tearfulness, irritability, aggression, and naughtiness aremore prevalent in children.
As glucose levels decline further, cerebral glucopenia occurs with drowsiness,
personality changes, mental confusion, and impaired judgment (moderate
hypoglycemia) progressing to inability to seek help and seizures or coma
(severe hypoglycemia). Prolonged severe hypoglycemia can result in a
depressed sensorium or Stroke like focal motor deficits that persist after the
hypoglycemia has resolved.
Although permanent sequelae are rare, severe hypoglycemia is frightening for
the child and family and can result in significant reluctance to attempt even
Moderate glycemic control afterward.
• Recurrent hypoglycemic episodes associated with tight metabolic
control may aggravate partial counter-regulatory deficiencies,
producing a syndrome of hypoglycemia unawareness and reduced
ability to restore euglycemia (hypoglycemia-associated autonomic
failure). Avoidance of hypoglycemia allows some recovery from this
unawareness syndrome
• The most important factors in the management of hypoglycemia are an understanding by the
patient and family of the symptoms and signs of the reaction and an anticipation of known
precipitating factors such as gym or sports activities. Tighter glucose control increases the risk.
• Families should be taught to look for typical hypoglycemic scenarios or patterns in the home
blood glucose log, so that they may adjust the insulin dose and avert predictable episodes.
• A source of emergency glucose should be available at all times and places, including at school
and during visits to friends. If possible, it is initially important to document the hypoglycemia
before treating, because some symptoms may not always be due to hypoglycemia.
• Most families and children develop a good sense for true hypoglycemic episodes and can
institute treatment before testing. Any child suspected of having a moderate to severe
hypoglycemic episode should also be treated before testing.
• It is important not to give too much glucose; 5-10 g should be given
as juice or a sugar-containing carbonated beverage or candy, and
the blood glucose checked 15-20 minutes later. Patients, parents,
and teachers should also be instructed in the administration of
glucagon when the child cannot take glucose orally.
• An injection kit should be kept at home and school. The
intramuscular dose is 0.5 mg if the child weighs less than 20 kg and
1.0 mg if more than 20 kg. This produces a brief release of glucose
from the liver. Glucagon often causes emesis, which precludes
giving oral supplementation if the blood glucose declines after the
glucagon effects have waned. Caretakers must then be prepared to
take the child to the hospital for IV glucose administration,
Dawn PhenomenonDawn Phenomenon• There are several reasons that blood glucose levels increase in the early morning
hours before breakfast. The most common is a simple decline in insulin levels and
is seen in many children using NPH or Lente as the basal insulin at supper or
bedtime. This usually results in routinely elevated morning glucose.
• The thought to be due mainly to overnight growth hormone secretion and
increased insulin clearance. It is a normal physiologic process seen in most
nondiabetic adolescents, who compensate with more insulin output. A child with
T1DM cannot compensate and may actually have declining insulin levels if using
evening NPH or Lente. The dawn phenomenon is usually recurrent and modestly
elevates most morning glucose levels.
Somogyi phenomenonSomogyi phenomenon• Rarely, high morning glucose is due to the Somogyi
phenomenon, a theoretical rebound from late night or
early morning hypoglycemia, thought to be due to an
exaggerated counter-regulatory response.
• It is unlikely to be a common cause, in that most children
remain hypoglycemic (do not rebound) once nighttime
glucose levels decline. Continuous glucose monitoring
systems may help clarify ambiguously elevated morning
glucose levels.
Management During Infections Management During Infections • Although infections are no more common in diabetic children than in nondiabetic
ones, they can often disrupt glucose control and may precipitate DKA.
• In addition, the diabetic child is at increased risk of dehydration if hyperglycemia
causes an osmotic diuresis or if ketosis causes emesis.
• Counter-regulatory hormones associated with stress blunt insulin action and
elevate glucose levels. If anorexia occurs, however, lack of caloric intake increases
the risk of hypoglycemia.
• Although children younger than 3 yr tend to become hypoglycemic and older
children tend toward hyperglycemia, the overall effect is unpredictable. Therefore,
frequent blood glucose monitoring and adjustment of insulin doses are essential
elements of sick day guidelines
• The overall goals are to maintain hydration, control glucose levels, and avoid
ketoacidosis.
• This can usually be done at home if proper sick day guidelines are followed and
with telephone contact with health care providers. The family should seek advice if
home treatment does not control ketonuria, hyperglycemia, or hypoglycemia, or if
the child shows signs of dehydration.
• A child with large ketonuria and emesis should be seen in the emergency
department for a general examination, to evaluate hydration, and to determine
whether ketoacidosis is present by checking serum electrolytes, glucose, pH, and
total CO2.
• A child whose blood glucose declines to less than 50-60 mg/dL (2.8-3.3 mmol/L)
and who cannot maintain oral intake may need IV glucose, especially if further
insulin is needed to control ketonemia.