The Barbados Health of the Nation Survey – Diabetic at Risk Feet Sub‐Study

Investigators:

Nigel Unwin, Chronic Disease Research Centre

Other Investigators:

Peter Adams (lead investigator) and Joseph Herbert, Faculty of Medical Sciences, Cave Hill Campus.

Funding Obtained:

Included within the total for the main study

Start Date:

October 2011

End Date:

December 2013

Rationale:

Previous work from the Chronic Disease Research Centre demonstrated one of the highest incidence rates of diabetes related amputations ever published. However, since this seminal work there has been no assessment of the proportion and characteristics of people with diabetes in Barbados who have ‘at risk’ feet, meaning who have evidence of peripheral neuropathy and/or peripheral vascular disease. Such data would help to plan and target ulceration and amputation prevention activities. This study takes advantage of the population based Health of the Nation Study in order to determine the prevalence of at risk feet in people with diabetes.

Methods:

All participants in the Health of the Nation Study who either reported a doctor diagnosis of diabetes, or who were identified as having raised fasting glucose (> 7mmol/l) or HBA1c (> 6.5%) were invited to participate. Examination for neuropathy included 10g monofilament testing at 4 plantar sites per foot, 128 Hz tuning fork and vibration perception threshold (VPT) bio‐thesiometer testing at the hallux. Examination for peripheral artery disease included measurement of ankle brachial index using Doppler ultrasound to detect blood flow.

Main Results and Further Analyses:

Out of 326 eligible participants (192 of whom reported a doctor diagnosis of diabetes), 237 attended for a foot examination. Using the monofilament 23.6% (95% CI 18.2‐29) 17.2%, 12.0% and 9.8% had a loss of sensation at ≥ 1,2,3 and 4 sites respectively; and 9.3% (95% CI 5.6‐13) had a vibration perception threshold of ≥ 25V, and 12.7% (95% CI 8.4‐17) did not detect the vibration of a tuning fork for at least one foot. Further analyses will examine the prevalence of peripheral arterial disease, and the predictors of ‘at risk’ feet.

Expected impact:

The findings from this study will be used to plan and target interventions aimed at reducing ulceration and amputation in people with diabetes in Barbados.

Next Steps / Future Plans:

Further analyses, as described above.

Publications:

Two main publications are planned. One describing the prevalence and predictors of peripheral neuropathy in this population by the different measures used in this study; the second describing the prevalence and predictors of at risk feet in this population.

Training opportunities:

Two junior doctors on the Family Medicine programme have received research experience and training through their contribution to this study.