This document summarizes epidemiological research on Parkinson's disease (PD) and associated risk factors. It finds that while the exact cause of PD is unknown, risk increases with age and is higher in males. Several genetic and environmental factors may also contribute to risk, including family history, head trauma, agricultural work, and low folate levels. The prevalence and incidence of PD varies globally but increases with age, affecting approximately 1% of those over 60.

1. Descriptive Epidemiology of
Parkinson’s Disease and
associated risk factors
By
Rana Das,
(Bsc. Hons. Medical biotech)

2. How we view the world…..
• Pessimist: The glass is half
empty.
• Optimist: The glass is half full.
• Epidemiologist: As compared to
what?

3. RIP..!!

4. Definition of Epidemiology*

5. Md. Ali affected with
Parkinson’s

6. Pope John Paul II

7. Origins of Parkinson’s
• Parkinson's disease was first formally described
in "An Essay on the Shaking Palsy," published in
1817 by a London physician named James
Parkinson
• It has probably existed for many thousands of
years
• Symptoms and potential therapies mentioned in:
• Ayurveda, the system of medicine practiced in India as
early as 5000 BC
• First Chinese medical text, Nei Jing, which appeared
2500 years ago

8. Etiology
• The cause of Parkinson’s disease is unknown.
• Many researchers believe that several factors
combined are involved: free radicals, accelerated
aging, environmental toxins, and genetic
predisposition.

9. What Causes Parkinson's?
• Why an individual develops Parkinson's
disease remains unclear.
• The cause is probably a combination of
genetic and environmental factors, and may
vary from person to person.
• Although the cause of Parkinson's remains
unknown, scientists have identified factors
that contribute to Parkinson's in some
patients.
• People over age 60 have a two-to-four percent risk
of developing Parkinson's disease, compared with
the one-to-two percent risk in the general
population.

10. Causes of Parkinson’s

11. On a cellular level
• Studies have shown that the accumulation of a protein alpha
synuclein in the neurons lead to the formation of lewy bodies
which inhibit the transmission of dopamine from one neuron
to other.
• Over production of alpha synuclein is related to mutaion in
the SYNCA gene.

12. Inhibition of Dopamine

13. Prevalence
How many people have PD?
 Estimated 1 million patients in US
 Second most common age-related
neurodegenerative disorder
 Second in frequency only to Alzheimer’s disease
 World-wide estimates vary
15/100,000 in China
657/100,000 in Argentina
100 - 250/100,000 in North America and Europe
 Prevalence is predicted to triple over the next 50
years as average age of population increases.

14. Incidence
 Quantifies the number of individuals who
are newly diagnosed with PD in a given time
period
 Unaffected by factors affecting disease
survival
 Accurate measurements of the incidence of
PD are relatively difficult
Clinical manifestations of PD may be preceded by a long
latent stage and have a slow clinical progression

15. Incidence
Difficult to know how many people are diagnosed each year:
 Symptoms may develop and progress slowly
 Diagnostic criteria may vary
 Patient populations vary with respect to doctor visits

16. Incidence
 China: 1.5/100,000
 Finland: 14.8/100,000
 US: 20/100,000
 Variations may be due to different diagnostic criteria and
methods of case ascertainment in studies
 Lifetime risk of PD: 1 in 40

17. Age
The incidence of PD increases with age
Symptoms of Parkinson’s disease may appear at any age
The median age of onset for idiopathic PD is 62.4 years
Onset before age 30 is rare, but up to 10% of cases of
idiopathic PD begin by age 40

18. Age
• Prevalence increases with age from age 50-90
• Affects 0.3% of general US population
• Affects 3% of those older than 65
• Aging alone does not cause PD
• May increase susceptibility to other factors or allow
them to be expressed

19. Gender
 Slightly more common in men than in women
Estimated 12-15 men for every 10
women

20. Ethnicity
 Present worldwide, in all populations
 No region found to be free of PD
 More common in white people in Europe
and North America
(100-350/100,000)
 Lower rates in China, Nigeria and Sardinia
 The disorder occurs in all races but is
somewhat more prevalent among Caucasians

21. Ethnicity
 Generally less common among African-
Americans and Asians
one-fifth to one-tenth as prevalent as in whites
 In Africa less common among blacks than
whites
 Door-to-door screening in Mississippi
PD prevalence was not significantly different in whites and
blacks after adjusting for age differences (poor diagnostic
criteria)
Higher prevalence in whites with stronger diagnostic
criteria

22. Ethnicity
 Two other studies conducted
 PD incidence in African-Americans and in Asian-
Americans was similar to rates for European-
Americans
 Door-to-door survey in Taiwan
Prevalence of PD =119/100,000
Similar to that of a white population and much
higher than that of previous studies of Asian
populations

23. Ethnicity
 Differences in findings
 Suggest environmental factors
more important than racial factors
 Further studies needed
Other factors?
Differences in access to
healthcare?

24. Ethnicity
• The disease was once thought to affect
primarily whites, but recent studies have
demonstrated equal prevalence in African
Americans and whites living in the same
geographic area.
• Comparative epidemiologic studies performed
in various major cities have yielded
contradictory information.
• Variations in the prevalence of the disease in
individual racial groups in different geographic
areas have suggested an increased risk
associated with rural living.

25. Time
 Hard to evaluate
 Few studies that track over long period of time
 Studies might use different methods or have
different diagnostic criteria
 Two studies  different conclusions
 Greater awareness - well-known people have
developed PD

26. Time
 Study in Olmsted, Minnesota
1935-1988
 Tracked number of people diagnosed with
PD each year
1935-1944: 9.2/100,000 diagnosed
1975-1984: 16.3/100,000 diagnosed

27. Time
 NIH study of world-wide PD trends
 Statistically controlled for age differences
 Concluded that the prevalence and incidence of PD appear to
have remained unchanged over the past 40 years.

28. Definition of a risk factor-
Risk factor is anything that increases your chances of getting
sick or having a problem. The onset of Parkinson’s disease is a
multi factorial process. However even if you have several
known risk factors, you might still not have PD(Parkinson’s
disease).

29. In July 2004, THE NATIONAL INSTITUTE OF HEALTH
(NIH)reported that more than two dozen genetic risk factors
involved in PD have been identified, among which 6 were such
which were reported for the first time. In a small number of
cases worldwide, there is a strong inheritance pattern for the
disease. In such cases the development of the disease is
basically due to an environmental toxin present or trauma or
an illness.

30. • Age
• Sex
• Family history
• Declining oestrogen level
• Agricultural work
• Levels of B vitamin folate
• Head trauma
• Free radicals

31. FFAACCTTOORRSS AASSSSOOCCIIAATTEEDD WWIITTHH
PPAARRKKIINNSSOONN’’SS DDIISSEEAASSEE
Advancing age-
Cases of young age development of the disease
has been noticed although the actual symptoms
occurs at a later age and keeps on getting worse
as one gets older. Researches have shown that
people with Parkinson’s have neural defects
which keeps getting worse as one gets older.

32. FFAACCTTOORRSS AASSSSOOCCIIAATTEEDD WWIITTHH
PPAARRKKIINNSSOONN’’SS DDIISSEEAASSEE
Sex-
Males are at higher risk of getting Parkinson’s disease than
females. Reason for this being that males are most exposed to
factors such as-head trauma or environmental toxins.
Researches have shown that oestrogen have neuro-protective
functions hence females are at lesser risk.

33. FFAACCTTOORRSS AASSSSOOCCIIAATTEEDD WWIITTHH
PPAARRKKIINNSSOONN’’SS DDIISSEEAASSEE
Familial history-
Having one or more closely related family member affected
by the disease increases your risk of developing the disease
too. But to a minimal degree. This lends support to the idea
that Parkinson’s Disease has a genetic link.

34. FFAACCTTOORRSS AASSSSOOCCIIAATTEEDD WWIITTHH
PPAARRKKIINNSSOONN’’SS DDIISSEEAASSEE
Declining oestrogen level-
• As a woman attains menopausal age, the levels of
oestrogen in the body decreases.
• As it known that oestrogen has neuro-protective functions,
low levels of oestrogen might result in the development of the
disease. Women not opting for hormone replacement
therapies are particularly ar risk.

35. FFAACCTTOORRSS AASSSSOOCCIIAATTEEDD WWIITTHH
PPAARRKKIINNSSOONN’’SS DDIISSEEAASSEE
Agriculture work-
Agricultural work expose you to several environmental toxins
which may cause PD as they inhibit dopamine production and
promote free radical damage. Farmers are at high risk due use
of pesticides and other chemicals.

36. FFAACCTTOORRSS AASSSSOOCCIIAATTEEDD WWIITTHH
PPAARRKKIINNSSOONN’’SS DDIISSEEAASSEE
Low levels of B vitamin folate-
Researchers have studied that mice which have a low level of
this vitamin develop severe Parkinson’s Disease whereas mice
with a normal level do not develop.

37. FFAACCTTOORRSS AASSSSOOCCIIAATTEEDD WWIITTHH
PPAARRKKIINNSSOONN’’SS DDIISSEEAASSEE
Head trauma-
Recent studies have found a link between injury to the head,
neck and cervical spine and Parkinson’s disease. In 2007,60
patients show trauma-induced upper cervical damage. Some
patients remembered a particular incident others did not. In
some cases Parkinson’s symptoms took decades to appear.

38. FFAACCTTOORRSS AASSSSOOCCIIAATTEEDD WWIITTHH
PPAARRKKIINNSSOONN’’SS DDIISSEEAASSEE
Free radicals-
Usually free radicals are formed in body and brain but they
eventually they are flushed out of the body due to mechanisms of
the brain and body. People with Parkinson’s disease don’t have
such mechanisms to flush out such free radicals. Environmental
toxins contribute to abnormal increase in free radicals and increase
in risk of Parkinson’s Disease.

39. THANK YOU