EndocrineDz&Exercise

7/30/2019 EndocrineDz&Exercise

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Exercise and Endocrine Care

Eric Sherman

MAJ, USAF, MCPediatric Endocrine Fellow


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Objectives

Discuss the maintenance of euglycemia

Review some basics of exercise physiology

Review exercise physiology in type 1diabetes

Review the literature on exercising safely

with type 1 diabetes Review other endocrine disorders and any

exercise recommendations


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Fasting state

Reduced insulin secretion

Increased levels of cortisol, GH, glucagon

and epinephrine Glucose production enhanced

Mobilization of fatty acids for energy

Sperling Pediatric Endocrinology


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Fed state

Increased insulin secretion (w/in 20-30 min)and decreased glucagon secretion

Glycogen synthesis enhancedEnhanced glucose uptake in muscle

Suppression of gluconeogenesis

Lipid synthesis activated and lipolysissuppressed

Sperling Pediatric Endocrinology


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After exercise

Similar to fasting state

Goal to rebuild skeletal muscle glycogen

stores

Increased GLUT4 transport (insulin not initially

required)

Full replenishment of muscle stores requiresinsulin

PierceBr. J. Sports Med(1999)


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Counter regulatory hormones

Cortisol (adrenal cortex)

Enhances gluconeogenesis

Epinephrine (adrenal medulla)More potent than norepi

Inhibit insulin secretion

Increase glucose secretion from liver andlactate from muscle

Norepinephrine (same as epi)Sperling Pediatric Endocrinology


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Insulin regimens

Traditional

NPH + regular (now Novolog/Humalog) in AM

Novolog at dinner

NPH at bedtime

Basal-bolus

Lantus once daily + Novolog at meals

CSII (insulin pump)

Intensive treatment


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Diabetes and exercise

1. Exercise may decrease risk of diabetes

complications

2. Hypoglycemia

3. Increased risk of DKA

4. Unmasking CAD


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What is different in diabetes

Constant non-physiologic insulin supply

Variable insulin absorption

Suboptimal release of counter-regulatoryhormones (especially during sleep)

Increased skeletal muscle uptake following

exercise Increased insulin sensitivity after exercise

McMahonJCEM(2007)


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Exercise physiology in diabetes

Decline in serum glucose

Decreased plasma

insulin secretion

Increased glucagon

secretion

Muscular glucose production

+

Fatty acids mobilized from adipose tissue+

Gluconeogenesis from lactate (liver)

+

GLUT4 stimulated transport of glucose into muscle

Increased counter-

regulatory hormones

Hypoglycemia


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Hypoglycemia

Older data suggests that risk of hypoglycemia lasts

up to 31 hours after exercise MacdonaldDiabetes Care (2007)

2-4% of deaths in type 1 diabetes attributed tohypoglycemia CryerDiabetes Care (2003)

2 episodes per week of severe hypoglycemia in

well controlled diabetics CryerDiabetes Care (2003)

One episode of hypoglycemia blunts responses to

subsequent hypoglycemia for several daysHopkinsDiabRes Clin Prac (2004)


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And now for some real data


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McMahonJCEM(2007)


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McMahonJCEM(2007)

Early hypoglycemia

Lack of physiologic decrease in insulin

secretion

Late hypoglycemia (MN4AM)

Imbalance between glucose production and use

Need to replete glycogen storesBlunted counter-regulatory responses during

sleep


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McMahonJCEM(2007)

Lack of hypoglycemia from 5PMN

Elevated counter-regulatory hormones may

have increased fatty acid oxidation

Fatty Acids Cortisol Growth Hormone


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How many carbs before exercise?

9 adult subjects on NPH and Novolog exercisedfor 60 minutes (50% VO2 max) with euglycemicclamp3 hours post breakfast

Given 0, 15 & 30 g of carbs prior to exercise

Based on GIR and amount of pre-exercise carbs, aregression equation calculated

35 g of carbs prevents acute hypoglycemia 40 g of carbs prevents acute and late

hypoglycemia DubeMed & Sci in Sports & Exercise (2005)


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Reduction in pre-meal insulin

8 adult males in randomized crossover trial

Exercised at 25, 50 & 75% of VO2 max for 30

and 60 minutes (90 minutes after eating)Injected 25, 50 & 100% of typical Humalog

dose

100% of Humalog dose associated with

significantly reduced BG compared withdose reduction (all groups)

RabasaLhoretDiabetes Care (2001)


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Insulin pumps

Is suspending them an option?

50 patients aged 8-17 in random crossover trial

(on and off pump during 75 minutes of exerciseat 55% VO2 max)

DirecNetDiabetes Care (2006)


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Hypoglycemia 3 times morecommon in basal continued

group

Hyperglycemia 4.5 times

more common in basal stopped

group

DirecNetDiabetes Care (2006)


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Another pump study

10 patients exercised for 45 minutes (60%

VO2 max) with pump on and pump off

Wore CGMS for 24 hours after exercise

No difference in hypoglycemic events

during exercise (2 in each group)

All 10 had 1-3 hypoglycemic events (BG

50-70) from 2.5 to 12 hours after exerciseAdmonPediatrics (2005)


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Higher intensity exercise

7 adults

30 minutes of moderate exercise (40% VO2

max)30 minutes of intermittent high intensity

exercise (40% VO2 max + 4s sprints every 2minutes)

IHE felt to mimic typical toddler activityand adolescent sports

GuelfiDiabetes Care (2005)


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Why the difference?

Lactate

Inhibit glucose uptake within skeletal muscle

Stimulate hepatic gluconeogenesis Catecholamines

Inhibit insulin mediated glucose uptake

Stimulate hepatic gluconeogenesis

GH

Inhibit insulin mediated glucose uptakeGuelfiDiabetes Care (2005)


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A novel approach

7 adult males with type 1 diabetes in

random crossover trial

Exercised for 20 minutes at 40% VO2 max +/-a 10 s sprint at completion of exercise

Theorized that a short sprint would prevent

hypoglycemiaIncrease in lactate & catecholamines

BussauDiabetes Care (2006)


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Lactate

Epinephrine

Glucagon

Growth

hormone

Norepinephrine

Cortisol

Insulin

Fatty

acids



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My recommendations

Avoid exercise if BG < 100 or > 300

Check ketones if BG > 250 and exercising

Take 15 g of carbohydrates for every 30minutes of exercise

Check BG every 30-60 minutes during

exercise and as needed Avoid using legs for injections p/t running

(increased absorption)abdomen better


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My recommendations

Check BG after exercise

Disconnect pump during moderate to high

intensity exercise, most sporting events andswimming

Check BG prior to bedtime and eat snack

with both carbohydrates and protein

Check BG at 2A on intense exercise days


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Insulin adjustment

Post exercise

Consider decrease in insulin dose of 25-50%

Elite athletes

50-75% reduction in total daily insulin dose

Hypoglycemia can occur up to 24-36 hours

after competition (restoring muscle glycogen)PierceBr J Sports Med(1999)


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Exercise & Hyperglycemia

Physiology

Insulin deficiency

Hepatic glucose production continues withoutglucose utilization (exaggerated

hyperglycemia)

Increased lipolysis leads to FA and ketone

production (exaggerated ketosis)

ZinkerClinics in Sports Med(1999)


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Preparticipation evaluation

Vital signs

Complete PE including monofilament evaluation

A1C Yearly eye exam

Microalbumin

Fasting lipid panel TFTs

Consider formal cardiac stress test


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Exercise & Retinopathy

ADA Position StatementDiabetes Care (2004)


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Exercise and Nephropathy

No specific recommendations

ADA says high intensity/strenuous exercise

should be avoided unless BP monitoringavailable

Treatment may limit exercise capacity



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Exercise and peripheral

neuropathy Loss of sensation in feet increases risk of

ulcers

Contraindicated AllowedTreadmill Swimming

Prolonged walking Biking

Jogging Rowing

Stairmaster Chair/armexercises



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Exercise & autonomic

dysfunction Difficult to diagnose

Resting HR > 100

Orthostasis

Delayed gastric emptying

Cardiac stress test


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Type 2 diabetes

Exercise benefits more clearly defined

HDL cholesterol, Total chol, LDL chol, TG

BP

insulin sensitivity

weight loss ( insulin resistance)

fatal cardiac events

Armen Clin Sports Med(2003)


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Type 2 Diabetes

Decreased risk of hypoglycemia whentaking oral agents

Insulin therapyIncidence of hypoglycemic events similar to

type 1 diabetics when patients matched forduration of insulin therapy HopkinsDiab Res Clin Prac (2004)

Increased carbohydrate intake and BGmonitoring prior to exercise recommendedDiabetes Care (2004)


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Hemodynamic changes in thyroid disease

Hyperthyroidism Hypothyroidism

Peripheral vascular resistance

Circulation time

Cardiac output

Stroke volume

Cardiac index

Arterial resistance

Venous resistance

Systolic/diastolic function

Systolic blood pressure

Pulse pressure widened narrow

Kahaly Thyroid(2002)


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Exercise and Hypothyroidism

No specific ATA recommendations

Limited data about exercise in treated

patients

Subclinical hypothyroidism

No change in exercise parameters after 1 year

of treatment (TSH 4.65 before treatment and1.28 after treatment)

CaraccioJCEM(2005)


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Exercise and Hyperthyroidism

No specific ATA recommendations

Increased metabolic state with increased O2

consumption

Increased risk of atrial fibrillation and

rhabdomyolysis

Kahaly Thyroid(2002)


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Exercise and Hyperthyroidism

What we recommend

Avoid exercise until T3 and T4 levels are

normalized (may take several weeks)TSH may remain suppressed for several months

(no impact on exercise tolerance)


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Brief case report

45 yo white male with sarcoidosis

Treated with prolonged steroid taper over 3

years (was on 2.5 mg/day at time of death)

On Atenolol for 1 year for HTN

Collapsed & died in June 1983 3.5 miles

into marathon in Sheffield, England

ParsonsBr J Sports Med(1984)


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Brief case report

Missed Prednisone 2 days prior to race and

on race day

Autopsy revealed cortical atrophy and lipiddepletion of adrenal glands (total weight 4

g)

ParsonsBr J Sports Med(1984)


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So what

LWPES and ESPE recommend that extra

steroid dosing be considered when

performing endurance sports

LWPES/ESPE Consensus Statement JCEM(2002)


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CAH and High Intensity Exercise

WeiseJCEM(2004)

Stress dose steroids??


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WeiseJCEM(2004)

Stress dose steroids??


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CAH and Prolonged Exercise

Green-GolanJCEM(2007)


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Review

Discussed the maintenance of euglycemia

Reviewed some basics of exercise physiology

Discussed exercise physiology in type 1 diabetes Reviewed the literature on exercising safely with

type 1 diabetes

Discussed other endocrine disorders and any

exercise recommendations


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Questions

Documents

EndocrineDz&Exercise