Here's a list of associations which David Ponsonby, PD researcher provided:

" The establishment tend to write in terms of co-morbid disorders i.e. Diabetes, Cancer... so I gathered a list of "Secondary Factors" of things that kept cropping up on Forums like this one. A formal connection with PD may not always exist - it came for constipation in the late '90s.... but here are some things that may worsen with PD or because of the meds that go along with PD etc.
Addiction
Bladder problems
Blepharitis (See under Seborrhea)
Cancer
Cognitive Disturbances
Constipation [see also Gastrointestinal Concerns]
CTS Dupuytren’s
Death see under Mortality
Dental care xerostomia (dry mouth)
Depression/ Suicide
Dermatitis
Drooling
Dysphagia / Dysphonia
Emergency (See also Falls & Hip Fractures i.e. Orthopaedic Approaches [PONS])
Falls (See also hip fractures)
Fatigue
Food Sensitivities
Foot Cramps
Frozen shoulder
Gait
Gastrointestinal Concerns:
Constipation / Drooling/ Dysphagia /
Gastroparesis / Irritable Bowel Syndrome / Peptic ulcer
Handwriting
Hearing
Hip Fracture
Hyperhidrosis
Hyposmia (See Smell)
Migraine
Olfaction (See Smell)
Orthostatic Hypotension
Hyperhidrosis (Excessive sweating)
Hypotension
Mortality
Pain
Psychosis (see Cognitive Disturbances: Hallucinations)
Seborrheic Dermatitis (Blepharitis)
Sexuality/Impotence
Sleep
Smell (Hyposmia/Olfaction)
Speech (see Voice)
Stress
Swallowing (see Dysphagia)
Vascular disease (hyperhomocysteinemia)
Vision
Voice (Speech see also Swallowing / Dysphagia)!

My original neurologist had asked if I had been exposed to chemicals while in the military. As a mechanic and soldier stationed overseas, that was a definite yes.

We believe my Dad's PD was linked to working on a farm and being exposes to various pesticides and chemicals that have been linked to PD. There is a higher prevalence of the disease in these folks. My grandfather demonstrated symptoms as well but was never diagnosed. There's also a higher prevalence among 3rd shift workers, I've read, which my dad did for 20 years as an ER nurse.

i have fibromyalgia and RLS, and both have overlapping symptoms of PD. i never know if something i feel is one thing or another. overlapping drugs as well

I suffer from alot of the things u listed, but bcuz of pd. I didn't have these issues until a yr after I was diagnosed