The purpose if the study is to determine whether improving sleep, especially slow wave or "deep" sleep, in older adults with osteoarthritis (OA) and insomnia reduces pain sensitivity and inflammatory responses to pain, and improves OA-related pain.

Inclusion Criteria:

• 50-75 years of age (for women, post-menopausal)
• Kellgren-Lawrence grade II radiographic evidence of OA affecting one or both knees
• knee pain on most days for ≥ 6 months
• self-reported disability due to knee pain for ≥ 2 of the following: walking, kneeling, ascending or descending stairs, or performing daily activities
• willing and able to avoid all prescription and non-prescription, non-opiate pain medication for 48 hours prior to testing and all narcotic pain medication for 2 weeks prior to testing
• meets research diagnostic criteria for sleep maintenance insomnia

Exclusion Criteria:

• health conditions with immunological components or undergoing or taking immunosuppressive therapies
• conditions contraindicated for or potentially limiting ability to conduct NFR and/or cold pressor test (e.g. Raynaud's syndrome; seizures; prior MI; respiratory conditions; leg/hip nerve damage; BMI ≥ 32)
• sleep disorders other than insomnia
• dementia or cognitive impairment
• history of schizophrenia or bipolar I disorder; current or recent history (within 3 months) of major psychiatric disorders
• current depressive symptomatology or current suicidality
• active substance dependence
• untreated hypertension
• use of antidepressants (stable use for 3 months okay), antipsychotics, mood stabilizers, sedative-hypnotics, opiate analgesics