Transcript High - University of Arkansas for Medical Sciences

Exercise
Diabetic
& Pregnancies
E. Albert Reece, M.D., Ph.D., M.B.A.
Dean and Vice Chancellor
College of Medicine
University of Arkansas for Medical Sciences
Benefits of Exercise
30 minutes of moderate
activity a day has many
health benefits:
• Exercise increases
muscular strength
• Exercise improves lung
capacity
• Exercise helps to control
weight
• Exercise helps to maintain
and may increase bone
density
Benefits of Exercise - 2
• Exercise protects against a variety of diseases:
- Heart disease
- Stroke
- High blood pressure
- Osteoporosis
- Diabetes
• Exercise has several
mental health benefits:
- Lowers stress
- Boosts mood
- Improves self-esteem
Metabolic Effects of Exercise
• Each day, 60-75% of total caloric expenditure is
used to maintain our resting metabolic rate
• Only about 15-30% of energy expenditure is
used for physical activity
• Exercise facilitates glucose
utilization secondary to
increase in insulin binding
and affinity to its receptor
Metabolic Effects of Exercise - 2
• Effects of exercise on lipids:
- Cholesterol drops 4-72 hours after
intensive prolonged exercise
- Plasma triglyceride falls acutely
after isolated exertion, possibly
secondary to increase in
lipoprotein activity with
secondary catabolism of triglyceride
Oscai et al., Am J Cardiol 1981
Metabolic Effects of Exercise - 3
Insulin Production
and Effects
Pancreas
Islets of
Langerhans
Beta Cell
Proinsulin
Amino Acids
Glucose
Insulin
Circulatory System
Insulin
Protein
Synthesis
Lipid Synthesis
Glucose
Amino Acids
Skeletal Muscle
Lipolysis
Stored in:
Gluconeogenesis
Liver
Adipose Tissue
Metabolic Effects of Exercise - 4
• Effects of exercise on plasma glucose uptake:
- Glucose uptake remains unchanged during
brief, moderate exertion
- Glucose uptake rises 15-20% during intense
exertion and falls gradually during prolonged
moderate work
- Glucose uptake continues to rise transiently
after exhaustive exercise and remains elevated
up to 30 minutes later
Wahren, et al., JCI 1971
Wahren, Diabetes, 1979
Metabolic Effects of Exercise - 5
- Plasma glucose is maintained by 2-5-fold
increase in hepatic glucose production, which
is secondary to gluconeogenesis as duration
of exertion increases
- Glucose uptake by muscle increases linearly
with exercise duration and intensity, reaching
50 times resting values at maximum effort
- Increase in glucose uptake occurs at very low
insulin concentration, but not in the absence of
circulating insulin
Calles, et al., Diabetes 1983
Katz, et al., AJP 1986
Berger, et al., JAPPL Physiol, 1989
Metabolic Effects of Exercise - 6
- Glucose uptake increases
after exertion in exercised
muscle vs. non-exercised
muscle for 4 hrs
- Glucose uptake is not
studied in insulinresistant pregnant
diabetic women
Katz, et al., AJP 1986
Berger, et al., JAPPL Physiol, 1989
Physiologic Changes
Associated with Pregnancy
• Hemodynamic changes include increase in
cardiac output, ventilation and oxygen
consumption
• Hyperventilation occurs normally; arterial CO2 is
10 mmHg lower postpartum
• Edema of lower extremities and shift in center of
gravity
Physiologic Changes Associated
with Pregnancy - 2
• Ligaments that support the joints become more
relaxed – joints become more mobile and are at
greater risk for injury
• Center of gravity shifts and places stress on
joints and muscles, especially in the pelvis and
lower back
Benefits of Exercise
During Pregnancy
Almost all women should be physically active
during pregnancy. Thirty minutes of moderate
exercise a day can provide many benefits:
• Exercise during pregnancy may help to prevent
gestational diabetes
• Exercise can help pregnant women to have
easier, shorter labor
ACOG, “Exercise During Pregnancy” pamphlet, 2003
Benefits of Exercise During Pregnancy - 2
• Exercise can promote faster recovery from
delivery
• Exercise can help to reduce pregnancy-related
discomforts:
- Back aches
- Leg cramps
- Constipation
- Bloating and swelling
• Exercise can help to improve mood and energy
levels
ACOG, “Exercise During Pregnancy” pamphlet, 2003
Safety of Exercise
in Pregnant Women
• Studies suggest exercise may
trigger premature labor,
mediated through enhanced
uterine activity
• Some investigators found no
effect on prevalence of
uterine contractions during
exercise
Safety of Exercise in Pregnant Women - 2
• One report suggests increased incidence of
prematurity and IUGR among mothers who
stood while working vs. sedentary workers
• U.S. collaborative perinatal project reported
reduction in mean birth weight in infants of
women who had jobs that required standing
Veille, et al., AJOG, 1985
Safety of Exercise in Pregnant Women - 3
• Most researchers use fetal heart rate as an
indicator of fetal distress and as a criterion for
disturbances in fetal gas exchange
• Some researchers have observed marked fetal
bradycardia during or after exercise; others have
not
• Controversy exists about analysis and
interpretations of fetal bradycardia
Artal, et al., Lancet 1984
Collings, AGOG 1985
Dale Can JAPP
Sports SCI 1982
Safety of Exercise in Pregnant Women - 4
Jovanovic Study on Safety
• Healthy women were recruited to exercise on 5
types of equipment that monitored blood
pressure, fetal heart rate and uterine activity
• Bicycle exercise caused uterine contractions
(50% of 25 sessions)
• Walking on treadmill produced contractions
when pace quickened to a jog (40% of 10
sessions)
Durak and Jovanovic, AJOG, 1990
Safety of Exercise in Pregnant Women - 5
Jovanovic Study on Safety
• Rowing associated with fewer problems if seat
was fixed and arms did most of the work (10% of
68 sessions)
• Recumbent bicycle exercise did not cause
contractions (0% of 20 sessions)
• Conclusion:
upper arm exercises proved to be the safest and
most accepted mode of exercise in pregnancy
Durak and Jovanovic, AJOG, 1990
Guidelines for Exercising
During Pregnancy
• Maternal heart rate should not exceed
140 beats per minute
• Strenuous activities should not exceed
15-min duration
• No exercise should be performed in
the supine position after the first
trimester of gestation
• Avoid standing still for long periods
of time
Guidelines for Exercising
During Pregnancy - 2
• Pregnant women should be evaluated
individually with respect to exercise program
• Diabetes is a relative contraindication to
vigorous physical activity
• Other contraindications include risk factors for
preterm labor, vaginal bleeding and premature
rupture of membranes
• Little data exist regarding efficacy of exercise in
pregnancy complicated by Type 1 diabetes
Choosing Safe Exercises
During Pregnancy
According to ACOG, many forms of exercise are
safe during pregnancy.
• Each woman should consult her
doctor for appropriate exercises
• Beginners may start with as little
as 5 min. a day
• Do not exercise until exhaustion.
ACOG, “Exercise During Pregnancy” pamphlet, 2003
Choosing Safe Exercises
During Pregnancy – 2
• Warning signs of overexertion:
- Vaginal bleeding
- Muscle weakness
- Dizziness
- Calf pain or swelling
- Increased shortness
- Uterine contractions
of breath
- Chest pain
- Headache
- Decreased fetal
movement
- Fluid leaking from
the vagina
ACOG, “Exercise During Pregnancy” pamphlet, 2003
Choosing Safe Exercises
During Pregnancy - 3
• Exercises generally considered to be safe
- Walking: gives a total body workout
- Swimming: water supports body weight, avoids
muscle strain
- Cycling: provides good aerobic workout; stay
with stationary or recumbent biking in late
pregnancy
- Aerobic classes: low-impact and water
aerobics
ACOG, “Exercise During Pregnancy” pamphlet, 2003
Exercise in Women
With Type 2 Diabetes
Moderate, sustained exercise can:
• Decrease blood glucose concentrations
• Lower plasma insulin concentration in
both fasting and postprandial states
• Increase insulin sensitivity
• Improve lipid profile
• Reduce hypertension, independent of
weight loss or change in body
composition
Exercise in Women With Type 2 Diabetes - 2
Results from two studies differ, describing glucose
levels following exercise:
• Artal and colleagues report a reduction in
glucose and free fatty acid levels, but
heightened epinephrine and norepinephrine
response
• Hollingsworth reports no significant improvement
in HBA1 levels
Artel, 1986
Hollingsworth, et al., AJOG 1987
Exercise in Women With Type 2 Diabetes - 3
• Exercise appears to be effective only as long as
training is continued
• Physical activity may be effective adjuncts to
other weight reduction strategies
• Metabolic effects may be less likely to occur
during pregnancy
Gestational Diabetes
and Exercise
• Gestational diabetes: carbohydrate intolerance
of variable severity with onset or first recognition
during pregnancy
• Similarities to Type 2:
- Abnormalities of insulin secretion and action
- Obesity
- Insulin resistance
- Abnormal first phase insulin release
• Is a strong predictor (approximately 50%) of later
IGT or Type 2
Horten, et al., Diabetes Suppl 1991
Gestational Diabetes and Exercise - 2
Two studies show positive results:
First study:
• 20 patients were randomized 2 groups
• One underwent 6 weeks of intensive dietary
therapy
• The other followed 6 weeks of dietary therapy
with 20 min. of supervised exercise 3x/day for 6
weeks
• All women exercised on arm ergometer
Jovanovic-Peterson, et al, AJOG, 1989
Gestational Diabetes and Exercise - 3
• Glycemic levels in 2 groups diverged by week 4
• By week 6, women in exercise group had
normalized hemoglobin A1, fasting postprandial
plasma glucose levels on 50 gm oral glucose
challenge
• Women in diet group improved but had severe
fasting and postprandial hyperglycemia
Jovanovic-Peterson, et al, AJOG, 1989
Gestational Diabetes and Exercise - 4
Second study
• Compared 6 weeks of arm crank exercise to
dietary therapy in gestational diabetes patients
with plasma glucose 84-106 mg/dL
• Exertional heart rate was kept at less than 140
and exercise occurred 3 times a week for 20
minutes
• In controls, fasting and plasma glucose fell from
98 to 88, and 1-hr post 50 gm glucose challenge
fell from 226-188.
Bung, et al., Diabetes 1991
Gestational Diabetes and Exercise - 5
• Improved glycemia occurred in exercise group
• Fasting glucose fell from 100 to 70
• 1-hr post 50 gm challenge fell from 231 to 106
mg/dL
• Conclusion:
- Exercise results in lower levels of glycemia
than diet alone
- Significant effects of exercise after only 4
weeks suggests that it could be started even at
28 weeks and still have therapeutic benefit on
fetal macrosomia
Complications of Exercise
in Diabetic Pregnant Women
• Glucose intolerance of Type 2 is reinforced by
the diabetogenic effects of pregnancy
• Effective reduction of fasting and postprandial
glucose levels has not been consistently
demonstrated
• Effects of exercise during pregnancy and
progression of diabetic vasculopathy is unknown
• ACE inhibitors retard progression of proteinuria
without worsening azotemia in patients with
nephropathy
Complications of Exercise
in Diabetic Pregnant Women - 2
• ACE inhibitors are contraindicated pregnancy
secondary to risk of IUGR, fetal loss and
neonatal hypotension
• In late pregnancy, venous return and cardiac
preload may be reduced after exertion leading to
reduced stroke volume and reduced cardiac
output
• The effect of autonomic neuropathy on exercise
safety is uncertain, especially at moderate
exercise intensities
Morton et al., AJOG 1985
Conclusion
• One-third of adult women in the U.S. are obese
• Only 1 in 6 pregnant women meet the current
physical activity recommendations of 30 or more
minutes of moderate physical activity a day
• During pregnancy, obese women are at
increased risk for adverse perinatal outcomes
- Spontaneous abortion
- Gestational hypertension
- Preeclampsia
- Gestational diabetes
- Fetal macrosomia
Johnson K. Ob. Gyn. News, Dec. 2005
ACOG Committee Opinion no. 315, Sept. 2005
Conclusion - 2
• Cesarean delivery rate was
20.7% for women with BMI
of 29.9 or less; 33.8% w/BMI of
30-34.9; 47.4% w/BMI of 35-39.9
• Studies show that exercise
is not associated with:
- Early pregnancy loss
- Late pregnancy complications
- Adverse neonatal outcomes
Johnson K. Ob. Gyn. News, Dec. 2005
ACOG Committee Opinion no. 315, Sept. 2005
Conclusion - 3
• Exercise is advocated as treatment for women
with GDM
• Those who are inactive or have complications
should be evaluated before initiating exercise
• Medical supervision is recommended for all
women with diabetes who exercise during
pregnancy
Metzger, Diabetes 1991
Dye et al., Am J Epidemiol 1997
Thank You