Depressive Symptoms and Lower Extremity Functioning in Men
and Women with Peripheral Arterial Disease
Mary McGrae McDermott, MD, Philip Greenland, MD, Jack M. Guralnik, MD, PhD,
Kiang Liu, PhD, Michael H. Criqui, MD, MPH, William H. Pearce, MD, Cheeling Chan, MS,
Joseph Schneider, MD, PhD, Leena Sharma, MD, Lloyd M. Taylor, MD, Adnan Arseven, MD,
Maureen Quann, BS, Lillian Celic, BS
OBJECTIVE: Factors associated with impaired functioning in
patients with lower extremity peripheral arterial disease (PAD)
are not fully understood. The purpose of this study was to
determine the relationship between depressive symptoms and
objective measures of lower extremity functioning in persons
with PAD.
DESIGN: Cross-sectional.
PATIENTS/PARTICIPANTS: Four hundred twenty-three men
and women with PAD identified from 3 Chicago area medical
centers.
MEASUREMENTS AND MAIN RESULTS: PAD was defined as
ankle brachial index (ABI) <0.90. The Geriatric Depression
Scale short form (GDS-S) (0±15 scale, 15 = worst) was
completed by all participants. A clinically significant
number of depressive symptoms was defined as a GDS-S
score 6. Six-minute walk distance and usual-and fast-pace
walking velocity were determined for all participants. A GDS-S
score 6 was present in 21.7% of participants with PAD.
Adjusting for age, increasing numbers of depressive symptoms
were associated with an increasing prevalence of leg pain on
exertion and rest (P = .004). Adjusting for age, sex, race, ABI,
number of comorbidities, current smoking, and antidepressant
medications, increasing numbers of depressive symptoms were
associated with shorter 6-minute walk distance (P < .001),
slower usual-pace walking velocity (P = .005), and slower fast-
pace walking velocity (P = .005). These relationships were
attenuated slightly after additional adjustment for presence
versus absence of leg pain on exertion and rest and severity of
exertional leg symptoms.
CONCLUSIONS: Among men and women with PAD, the
prevalence of a clinically significant number of depressive
symptoms is high. Greater numbers of depressive symptoms
are associated with greater impairment in lower extremity
functioning. Further study is needed to determine whether
identifying and treating depressive symptoms in PAD is
associated with improved lower extremity functioning.
KEY WORDS: depression; peripheral vascular disease; physical
functioning.
J GEN INTERN MED 2003;18:461±467.
S
tudies of community-dwelling older men and women
show that depressive symptoms are risk factors for
disability and that disability is associated with an increased
risk of depressive symptoms.
1±4
Disability may induce
depressive symptoms because of disability-associated loss
of social functioning and loss of independence in the
community. Depressive symptoms may induce subsequent
functional decline by way of several psychologically and/or
biologically mediated pathways.
4
For example, depressive
symptoms may reduce initiative to seek necessary medical
assistance for specific medical problems. Depressive
symptoms also may inhibit healthy behaviors integral to
improving functioning and mobility. Finally, by inducing
immunosuppression and/or by increasing sympathetic
tone, depressive symptoms may promote susceptibility to
infections and other diseases that may in turn further
impair functioning.
5±7
Patients with lower extremity peripheral arterial dis-
ease (PAD) have reduced lower extremity functioning as
compared to individuals without PAD,
8±10
and greater
severity of PAD as measured by the ankle brachial index
(ABI) is associated with greater impairment of lower
extremity functioning.
9,10
Patients with ABI <0.50, consis-
tent with severe PAD, are nearly 12 times more likely to
stop during a 6-minute walk test compared to individuals
with a normal ABI.
9
Because of their high burden of
functional impairment, patients with PAD may have an
increased prevalence of depressive symptoms. However,
the prevalence of depressive symptoms in patients with
PAD has not been well studied.
We documented the relation between depressive
symptoms and lower extremity functioning in persons with
PAD. Because persons with PAD already have impaired
functioning as compared to persons without PAD, it is not
clear whether depressive symptoms in patients with PAD
are associated with greater impairment in lower extremity
Received from the Department of Medicine (MMM, PG, LS, AA,
MQ, LC), Department of Preventive Medicine (MMM, PG, KL,
CC), and Division of Vascular Surgery, Department of Surgery
(WHP, JS), Feinberg Schoolof Medicine at Northwestern
University, Chicago, Ill; Laboratory of Epidemiology, Demogra-
phy, and Biometry, NationalInstitute on Aging (JMG), National
Institutes of Health, Bethesda, Md; Department of Family and
Preventive Medicine (MHC), University of California at San
Diego, San Diego, Calif; Division of Vascular Surgery, Depart-
ment of Surgery (JS), Evanston Hospital, Evanston, Ill; and
Division of Vascular Surgery, Department of Surgery (LMT),
Oregon Health Sciences Medical Center, Portland, Ore.
Presented in part at the nationalmeeting of the Society of
GeneralInternalMedicine, May 4, 2002, Atlanta, Ga.
Address correspondence and requests for reprints to Dr.
McDermott: 675 N. St. Clair, Suite 18-200, Chicago, IL 60611
(e-mail: mdm608@northwestern.edu).
461