Insulin Therapy and Falls Due to Orthostatic Hypotension

Insulin Therapy and Falls Due to Orthostatic Hypotension (Pilot Study)

In the proposed study, the investigators examine in older adults with Type 2 diabetes the impact of beginning insulin therapy on the orthostatic drop in blood pressure as well as the response of arterial blood pressure and Doppler measures of cerebral blood flow during upright tilt. The investigators hypothesize that in older adults with Type 2 diabetes, the cardiovascular effects of insulin would precipitate or worsen orthostatic intolerance not present at baseline.

Before and 2 weeks after the start of standard insulin therapy several tests will be done:

• orthostatic hypotension will be tested for with 3 orthostatic maneuvers
• vasovagal syncope will be tested with 2 tilt table tests, one augmented with 400ug of nitroglycerin
• MCA velocity will be measured with a transcranial doppler
• Heart Rate and Blood Pressure will be measured throughout the test with a Finometer and Power Lab on a beat to beat basis

Inclusion Criteria:

• All subjects must be 65 years of age or older
• All must have been diagnosed with Type 2 diabetes for at least 5 years
• All subjects must be insulin-naïve on recruitment
• All subjects must be eligible to start insulin therapy (long or intermediate acting) as determined by their diabetologist

Exclusion Criteria:

• Anemia, as determined by serum hematocrit
• Abnormal liver function tests
• Elevated creatinine
• Smoker
• Musculoskeletal or neurological condition that would preclude tilt table testing or orthostatic vitals