The author provides a startling expose on today's
diabetic epidemic and factors affecting the hearing
impaired population Diabetes Mellitus & Hearing Health
2003
By Max Stanley. Chartrand, M.A., DigiCare Hearing
Research & Rehabilitation
(Reprinted from Audiology Online July 30, 2003)
Research findings in diabetes and hearing loss continue
to affirm their related and positive correlation.
Although one cannot say with certainty that having a
specific type or degree of diabetes will absolutely
cause a specific type and degree of hearing loss,
research does indicate a clear clinical trend has
emerged. Dispensing professionals on the front lines
grapple with a host of complications and anomalies
presented by diabetic patients during the evaluation and
fitting process. Information and education about these
interrelationships is of utmost importance for patients
and professionals in an effort to minimize fitting
problems and to enhance post-fitting outcomes in the
diabetic patient.
The number of patients presenting with signs and
symptoms of diabetes mellitus, and the inherent risk
factors for diabetes mellitus, has steadily increased
over the past 20 years---not only in the United States,
but worldwide. 1, 2 It is no surprise that hearing
health professionals are increasingly listing diabetes
and secondary conditions, and the plethora of related
treatment medications in patient health histories.
To summarize, a few of the considerations affecting
hearing aid fittings with regard to diabetic patients
include:
·Increased hypersensitivity to earmold plastics due to
epithelial atrophy (tissue deterioration) in the ear
canal. Epithelial atrophy may sometimes be accommodated
via hypoallergenic shell materials. Some shell labs
offer removal or absence of color pigmentation to
achieve a hypoallergenic shell, and some offer clear or
translucent hearing aid shells.3 Other options are
available and should be discussed with the shell lab.
· The tendency to exhibit or present with malformation,
or early desquamation, of keratin protein (stratum
corneum) in the ear canal. When desquamation combines
with a low pH environment to cause chronic irritation
due to fungus and candida growth and bacterial infection
(otitis externa) can occur. When earmolds and custom
made hearing aid shells are inserted in the ear canal of
a diabetic patient, there is increased possibility that
the anaerobic environment of the external meatus may
encourage chronic or acute growth of amoebas, such as
psuedomonas.4 Medical management by a physician may
prove necessary, in addition to other professionals
involved with the hearing aid fitting.
·Higher-than-usual incidence of abnormal loudness growth
perceptions. Abnormal loudness growth may present as
either recruitment or decruitment from the cochlea, or
in some cases may exist at the ganglia neural level due
to neuropathy, a common complication of diabetes
mellitus. Loudness growth issues may be accommodated by
flexible and measurable compression and time-based DSP
amplification strategies.5, 6 · Vestibular problems
(dizziness, vertigo) may present within the diabetic
patient. While not directly affecting hearing loss,
hypersensitivity of the vagus nerve (a branch of Cranial
Nerve X that communicates nausea from the stomach area)
may be affected with an overly tight earmold. This, in
turn, may require a lessening of earmold pressure on the
branch of the vagus (Arnold’s branch), which travels
across the posterior and/or anterior wall of most ear
canals.7
· Higher incidence of central auditory involvement in
both receptive (speech understanding) and expressive
(speech) communication, including other complications
resulting from neural demyelination or auditory
neuropathy, in general.8, 9 Non-recognition of this
possibility can create unrealistic expectations and
failure to fit successfully.
Diabetes Prevalence and Cost to Society in the U.S.A.
Recognized cases of diabetes mellitus (those reported to
the Center for Disease Control) in the United States
number approximately 11.1 million, with another 6-8
million undiagnosed cases, making an estimated total of
more than 17 million cases. This figure does not account
for another 16 million pre-diabetic cases, such as
hypoglycemia (low blood sugar) and hyperglycemia (high
blood sugar).10 When these two populations are combined,
an estimated 33 million potential diabetes-related
patients emerge, representing more than ten percent of
the population of the U.S.A.
Gestational diabetes affects approximately 4-7% of all
pregnant women or about 135,000-200,000 cases per year,
causing numerous miscarriages and abortions. 11, 12, 13
Regarding lower extremity amputations (LEA) among
diabetics in the U.S., approximately 86,000 such
procedures are performed annually in the United States.
About 1/3 of all diabetics are at risk for amputation
during their lifetime.14
In 1997 alone, aggregate medical expenses directly and
indirectly attributed to diabetes, cost individuals and
society a whopping $78 billion, or $10,071 per diabetic
patient, making this one of the biggest, most avoidable
drains on the U.S. healthcare system.15
Regarding genetic influences, diabetic complications may
cause those with mitochondrial genetic mutation (tRNAleu)
to suffer greater hearing loss, including secondary
ototoxicity to aminoglycoside antibiotics (i.e.,
streptomycin, amikacin, tobramycin, and gentamycin).
Related renal dysfunction can also cause increased
ototoxic experiences with a host of other medications
and substances, as well (i.e., aspirin, aspertame,
monosodium glutamate, etc.).18 Because of this, timely
communication and observation between health
professionals, including those concerned with hearing
health, is extremely important in cases of diabetes.19,
20, 21
Many secondary and related conditions---hypertension,
hyperlipidemia, obesity, and artheriosclerosis, to name
but a few---are also on the rise in the general
population.22, 23 Although there have already been many
studies, which point to the interrelationship between
diabetes and hearing impairment, the Department of
Veterans is conducting a new study on veterans (age
21-80 years) to shed further light on potential
interrelationships with hearing loss and these related
conditions.24
Moreover, all of these numbers are on the rise, as
diabetes has been declared to now be in epidemic
proportions not only in the U.S., but worldwide.16, 17
These data should alarm hearing healthcare professionals
as the incidence of hearing loss among diabetics is
several times that of the non-diabetic population.
Consequently, as cited above, hearing health and
amplification fitting complications created by diabetes
and related pre-diabetic disorders, pose additional
challenges in the ongoing quest to habilitate and
rehabilitate auditory and other communicative
disorders.Types and
General Age Groups of Diabetes
Diabetes mellitus is characterized by abnormally high
levels of sugar (glucose), both in the blood and the
urine. Diabetes occurs when the body does not produce
adequate quantities (or the appropriate quality) of the
hormone insulin. Insulin is normally produced and
secreted by the pancreas. When diabetes occurs, the
cells of the body are unable to absorb glucose, leaving
excessive glucose in the bloodstream to wreak havoc with
serum chemistry. The excessive glucose is then passed
out of the body in the urine.25, 26 There are two basic
classifications of diabetes mellitus:
Type I, or insulin-dependent diabetes, is generally
recognized as juvenile diabetes, although it may occur
at any age. Affecting, about 5-8% of total diagnosed
diabetics, Type I diabetes can be life-threatening if
left untreated. Without medical attention, ketoacidosis
will develop, which can cause any number of health
problems, including blindness, weight loss, neuropathy,
comprised immunology, amputation or death. Ages of those
diagnosed with Type I diabetes generally ranges from 8
to 40 years. Type I is generally managed with daily
insulin, diet, and control of body energy. The
relationship between hearing loss and Type I diabetes
has been determined to be conclusive in numerous
studies, showing that many sufferers, depending upon
length of time and efficacy of treatment, exhibit a
somewhat less efficient auditory function, as compared
to their non-diabetic counterparts.
Type II primarily affects adults, especially those over
40 years of age. Slightly more women than men experience
Type II diabetes, and it tends to run in families
(mitochondrial inheritance). In these cases, the
pancreas produces insulin, but not the type and quality
needed by the body. Therefore, a combination of
non-insulin (and, less frequently, insulin) medications,
diet, exercise, and weight control is the usual
treatment course. Type II is also associated with being
overweight (and hyperlipoproteinemia) in about 80% of
cases.
A complication of treating diabetes mellitus is the
tendency toward weight gain, complete loss of pancreatic
function, and worsening heart disease. Each of these
possible treatment side-effects also affect hearing
health status, though only periodic audiometric
evaluations can confirm these changes of the auditory
system. Sometimes other health and age-related factors
can obscure these connections.27Need for Recognition and
Accommodation
By recognizing and openly discussing the effects of
diabetes and associated conditions on the auditory and
vestibular systems with patients, many potential
pitfalls may be avoided during the hearing habilitation
and rehabilitation process, with particular attention on
hearing aid fittings.
In hearing aid fittings on diabetic patients, the old
saying "finding the problem makes it half-solved" is
especially true. Appropriate accommodations made in the
hearing aid fitting process and acceptance of
limitations outside the control of the involved parties,
may alleviate an otherwise unfortunate rehabilitative
experience. Some prominently associated affects of
diabetes upon hearing loss and hearing aid fittings
include tissue hyper-sensitivity and the inability to
stave off infection (as was previously mentioned).
However, diabetes presents even greater subtle
challenges within the auditory and vestibular systems.
Other pronounced effects involve cochlear microphonics.
The cochlea converts hydraulic vibrations into
electrical impulses carried by the neural system of the
auditory nerve. To produce the proper electrical charge
(also called cochlear potential), there must be a
precise pH balance across the two inner ear fluids: 90%
potassium and 10% sodium for endoplymph, and 90% sodium
and 10% potassium for perilymph.
Other deleterious aspects of diabetes affect adequate
blood circulation in the stria vascularis, which is
comprised of millions of tiny capillaries that deliver
oxygen and nutrients to the cochleovestibular organ.
Cardiovascular disease complicated by diabetes affects
the circulatory system of the human ear.
Likewise, hypertension, and other fluid abnormalities
may have a direct effect upon inner ear function. When
the body’s pH balance is abnormal (too much acid or
alkalinity) or proper fluid level and circulation is
affected as aresult of fluctuations in the diabetic
condition, changes in loudness growth perception,
auditory thresholds and overall auditory function may
develop.
For this reason, a diabetic hearing aid user’s inability
to sustain abnormal loudness growth may require periodic
adjustment to accommodate fluctuating loudness sensation
needs. Many forms of digital technology/software-based
accommodation in hearing aid circuitry are almost
universally available throughout the hearing aid
industry today.
In fact, it is the opinion of this author that nearly
every case of hearing impairment with accompanying
diabetes may be effectively ameliorated with a holistic
approach to aural rehabilitation. This involves: medical
management, hearing instrumentation, AR counseling,
assistive listening devices, and training in
coping/repair strategies.
In cases of diabetic patients, it is advisable to
request (by informed consent) copies of medical reports
and lists of medication to be included in patient files.
This information could dramatically enhance the efficacy
of the case history, hearing evaluation, and
recommendation for amplification.
Furthermore, this information will assist in the
counseling and post-fitting process by helping diabetic
patients identify positive, quality-of-life enhanced
outcomes. And finally, it will assure better
communication and coordination between all members of
the community hearing health team.
M. S. Chartrand serves as Director of Research at
DigiCare Hearing Research & Rehabilitation.
Correspondence: www.digicare.org. References: 1.
Mokdad, A, Ford, E, Bowman, B, et al, "Diabetes Trends
in the United States, 1990-1998", Diabetes Care,
23:1278-1283 (2000).2. Must, A., Spadano, J, Coakley,
EH, Field, AE, Colditz, G, Dietz, WH, "The disease
burden associated with overweight and obesity", JAMA,
282:1523-1529 (1999).3. Chartrand, MS, Hearing Aid
Repair & Modification For Dispensers, Rye, CO:Unimax
Educational Publications, pp. 69-93, (1989).4. Chartrand,
MS, "The FDA Red Flags: Video Otoscopy Observation &
Referral", The Hearing Professional, Jan-Feb issue,
pp.9-14, (2003).5. Doyle, ND, Hoffman, JE, "General
Medical Considerations in Audiology", in Katz, J, ed.,
Handbook of Clinical Audiology, 2nd edition, Baltimore:
Williams & Wilkins, pp. 39-47 (1981).6. "Diabetes
Mellitus and Hearing Loss", http://web.uvic.ca/-esg02/ling482/ass3pages/smorrison/.html
(2003).7. Chartrand, MS, Hearing Instrument Counseling:
Practical Applications for Counseling the Hearing
Impaired, 2nd edition, Livonia, MI:International
Institute for Hearing Instruments Studies (1999).8.
Willott, JF, Aging and the Auditory System: Anatomy,
Physiology and Psychoacoustics, San Diego:Singular
Publishing Group, pp.82-84 (1991).9. Brunt, MA, Auditory
Sequela of Diabetes Mellitus, (PhD dissertation),
University of Kansas (1969).10. American Diabetes
Association, www.diabetes.org (2003).11. National
Institutes for Health, http://www.nichd.nih.gov/publication/pubs/gest_diabetes/.html
(2003).12. The Whole Truth About Contraception: A Guide
to Safe and Effective Choices, Chapter 18, Joseph Henry
Press, pg. 231, http://www.nap.edu/books/030905494X/html/231.html
(1997).13. Mokdad, A, Ford, E, Bowman, B, et al, "The
continuing epidemic of obesity and diabetes in the
United States", JAMA, 286:1195-1200 (2001).14. Vinicor,
F, "Diabetes: Preventing Lower-Extremity Amputations",
InMotion, Vol. 11, Issue 2, March/April, pp.15-17
(2001).15. American Diabetes Association, "Economic
consequences of diabetes mellitus in the U.S. in 1997",
Diabetes Care, 24(2):412 (2001).16. Mokdad, AH, Serdula,
MK, Diez, WH, et al, "The spread of obesity epidemic in
the United States, 1991-1998", JAMA, 282:1519-1522
(1999).17. Harris, MI, Flegal, KM, Cowie, CC, et al,
"Prevalence of diabetes, impaired fasting glucose, and
impaired glucose tolerance in U.S. adults: the third
National Health and Nutrition Examination Survey,
1988-1994", Diabetes Care, 21:518-524 (1998). 18.
Mitochondrial Gene Testing, Harvard University, http://hearing.edu/tests/mitochondrial.pdf
(2003)19. Chartrand, MS, "Diabetes and Hearing Health",
Hearing Health, June/July, pp. 10-12 (1992).20.
Chartrand, MS, and Anton LJ: "Hearing Health Assessment
and Case History," Advanced Audiometric Course,
Gainesville, TX: Unimax Professional Education
(1991).21. Jerger J. & Jerger S, Auditory Disorders,
Boston: Little, Brown and Company (1981).22. Ford, ES,
Williamson, DF, Liu, S, "Weight change and diabetes
incidence: Findings from a national co-hort of U.S.
adults", Am J Epidemiol, 146:214-222 (1997).23.
Fago-Campagna, A, Pettitt, DJ, Engelgua, MM, et al,
"Type 2 diabetes among North American children and
adolescents: an epidemiologic review and a public health
perspective", J Pediatr, 136:664-672 (2000).24. Fausti,
S (principal investigator), Epidemiology of Hearing Loss
in Diabetic and Non-Diabetic Veterans, VA Medical
Center, Portland, 97201 (2003).25. Basic information on
diabetes, www.diabetes.org (2003).26. Zelenka J. Kozak
P: "Disorder in Blood Supply of the Inner Ear as Early
Symptom of Diabetic Angiopathy," J Laryngol. Otol., 79
(1965).27. Hosler, AS, Melnick, TA, and Baker, CT,
"Prevalence of Activity Limitation among Adults in New
York State, 1993-1998", New York State Department of
Health, Spring (2002). |
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