Sickle Trait in Athletes

Andy Peterson MD MSPH

Sickle Cell Disease/Trait

• Substitution of a valine for glutamic acid as the sixth amino acid of the beta globin chain.

• Poorly soluble (alpha2-betaS2) hemoglobin

• Sickles and sticks together when deoxygenated

Sickle Cell Disease• SS disease - rare in athletes• Vaso-occlusive crises

– “A vicious viscous cycle”• Frequent ischemic injuries

– Dactylitis– Lung = acute chest– Stroke– Splenic Sequestration– Kidney Infarct (papillary necrosis)– Rhabdomyolysis– Bone Marrow Failure– Priapism– Soft tissue/ulcers/painful crisis

• Infections (pneumococcus, salmonella)• Significant Disability• Early Death

– Median life expectancy 45 years1

1. Platt, OS, Brambilla, DJ, Rosse, WF, et al. Mortality in sickle cell disease: Life expectancy and risk factors for early death. N Engl J Med 1994; 330:1639.

Sickle Trait• Hgb AS

• No hematologic findings

• 25 million Americans

• 8.5% of African Americans

• Inconsequential in most people

Challenges• Exercise

• Altitude

• Heat

Rare complications

• Splenic infarct at altitude

• Papillary necrosis

• Rhabdomyolysis

Splenic Infarct

• Ryan Clark at Denver• 2005 – “Splenic contusion”• 2007 – splenectomy• 2009 – held out

Splenic Infarct• Acclimatize

• Can occur as low as 5500 feet

• Presents with– LUQ pain– Nausea – Vomiting

• Commonly misdiagnosed

Splenic Infarct• Descend

• Rest

• Hydration

• Oxygen

• Rarely splenectomy

Hematuria• Papillary necrosis• Sickling in medula• Hyposthenuria

Hematuria/Papillary necrosis

• Hydrate

• Hydrate

• Hydrate

• Hydrate

• Hydrate

• Avoid 2nd kidney injury

Sudden Death With Sickle Trait• Sudden death among 2 million military recruits 1977-1981:

– 32.2/100,000 black recruits with AS – 1.2/100,000 black recruits without hgb S – 0.7 in nonblack recruits without hgb S

• 3 Army recruits 2008-2010– All trying to make 2 mile time standard

Kark, JA, Posey, DM, Schumacher, HR, et al. Sickle cell trait as a risk factor for sudden death in physical training. N Engl J Med 1987; 317:781

Sudden Death With Sickle Trait• Most deaths occurred during basic

training1

• Most occurred during 1-3 mile runs2

• Sudden collapse was rare - most deaths 2 hours to 2 days later (rhabomyolitis)2

• Risk of fulminant exertional rhabdomyolitis 200-fold higher in AS2

1. Kark and Ward. Exercise and hemoglobin S. Semin In Hematol. 31:181-225.

2. Gardner and Kark. Fatal rhabdomolitis presenting as mild heat ilness in military training. Milit Med. 159:160-163.

Sudden Death With Sickle Trait

• Martin et al. Am J Med. 1989.– Exercised 15 military recruits with AS– Maximal exercise at 1270m and Sim4000m– 1270m = 2.3% sickled cells– Sim4000m = 8.5% sickled cells– One recruit had 25% sickled cells and vSpO2

28%

NCAA Football 2000-2010• No deaths on the field of play• 16 conditioning deaths• 1 weight lifting• 15 running or agility• 4 Cardiac• 1 Asthma• 1 Exertional Heat Stroke• 10 SCT

Math• 10 SCT deaths

• 5 non-SCT deaths

• 3-4% prevalence of SCT

= RR 16-21!

The other math• 1/25,000 die of SCT per year

• 0.5/25,000 die of non-SCT per year

= 0.00004 absolute risk increase/year

(4/1,000th of a percent attributable risk)

• If limit to AA’s, 0.00008 ARI

10 most recent football SCT deaths

• #5 serial sprints for 5 to 25 minutes

• #4 fast-tempo, multi-station drills with short rest

• #1 gassers for 30 minutes

– 1974 Colorado Ran 700m– 1985 Arkansas Ran 3/4 mile– 1986 Mississippi Ran 1 mile– 1987 Indiana Ran 1200m– 1989 Utah Ran 3/4 mile– 1990 New Mexico Ran 800m– 1992 Georgia Ran 1000m– 1995 Arizona Ran 900m– 2000 Tennessee Ran 800m– 2001 Florida Intense drills 1h– 2004 Ohio Ran for 10 minutes– 2005 Missouri Field Drill 1h– 2006 Texas Ran 1600m– 2008 Florida Drills– 2008 North Carolina Ran hill 15 times– 2009 North Carolina Ran 700 yards– 2010 Mississippi Station Drills

• Common AS sickling situations– Running for time– Suicides/gassers– Hard efforts 800-1200m– High heat– Dehydration– Altitude– Early in workouts

• Multiple other studies support– Weisman et al. Clin Res. 1988– Weisman et al. Am Rev Resp Dis. 1988– Gozal et al. Med Sci Sports Exerc. 1992– Freund et al. Int J Sports Med. 1995– Bile et al. Med Sci Sports Exerc. 1996– Sara et al. Clin J Sport Med. 2003– Bergeron et al. Clin J Sport Med. 2004– Marlin et al. Int J Sports Med. 2005– Connes et al. Eur J Appl Physiol. 2006– Monchanin et al. Med Sci Sports Exerc. 2006

• Heat Cramps– Early warning signs– More painful/locking– Pain stops exercise– “Hobble to a halt”– Rock hard muscles– Slow response to Tx

• Sickling– Abrupt onset - no warn– Less painful

(claudication)– Weakness stops

exercise– “Slump to a stop”– Soft muscles– Rapid response to Tx

Management/Prevention• Acclimation• Progressive adaptation• Increased time between hard efforts• Pre-hydrate• Respond quickly

– Cool– Hydrate– Oxygen– Have AED ready if Sx

SPORT SPECIFFICCONDITIONING!

– 1974 Colorado Ran 700m– 1985 Arkansas Ran 3/4 mile– 1986 Mississippi Ran 1 mile– 1987 Indiana Ran 1200m– 1989 Utah Ran 3/4 mile– 1990 New Mexico Ran 800m– 1992 Georgia Ran 1000m– 1995 Arizona Ran 900m– 2000 Tennessee Ran 800m– 2001 Florida Intense drills 1h– 2004 Ohio Ran for 10 minutes– 2005 Missouri Field Drill 1h– 2006 Texas Ran 1600m– 2008 Florida Drills– 2008 North Carolina Ran hill 15 times– 2009 North Carolina Ran 700 yards– 2010 Mississippi Station Drills

Dale Lloyd II• Rice 2006• Family sued NCAA• Required screening

NCAA emphasis• Year round

conditioning• Longer rest• Symptom recognition• Modification at

altitude• Hydration• Set own pace• Build slowly

• Adequate rest• Sport specific

conditioning• Avoid exercise with

illness• Supplemental O2 at

altitude• Climate of

acceptance

Questions