How to Identify PAD in Diabetic Patients — A Guide for Primary Care Physicians

What is “Primary Care Physician”?

For clarity: by PCP I mean the generalist physicians or family doctors who manage diabetes in outpatient settings (clinics, health centers) — performing regular follow-ups, assessing complications, prescribing basic investigations, and deciding whether to refer to specialists. They are often the gateway for recognizing early signs of PAD in diabetic populations.

Why Detect PAD Early in Diabetic Patients

• Diabetes mellitus increases the risk of PAD by accelerating atherosclerosis, promoting micro- and macrovascular damage.
  

• PAD in diabetics tends to progress silently: early disease may have no pain, because of neuropathy or reduced physical activity.
  

• Undetected PAD increases risk of foot ulcers, non-healing wounds, infection, and ultimately amputation.
  

PAD is also a marker of systemic vascular disease; its presence forecasts higher risk of cardiovascular events (e.g., myocardial infarction, stroke).

Who to Screen / When to Be Suspicious

You should consider screening or further assessment for PAD in diabetic patients with one or more of the following:

Risk Factors

• Age ≥ 50 years : Higher prevalence of PAD with age.

• Long duration of diabetes (≥10 years) : More cumulative vascular damage.

• Presence of other atherosclerotic risk factors (smoking, hypertension, dyslipidemia): These accelerate arterial narrowing.

• Microvascular complications (neuropathy, nephropathy, retinopathy): Suggests systemic vascular involvement.

• History of foot ulceration, non-healing wounds, or prior amputation: Already indicates compromised circulation.

In Mauritius, recent data (WHO’s national framework, diabetic foot care services) show a high burden of foot complications; many patients present late. (WHO report: Mauritius had 403 new amputations in diabetic patients in 2022 vs 211 in 2008) World Health Organization

Clinical Signs and History to Elicit

During diabetes follow-ups, include PAD assessment in history and physical exam as follows:

History

• Ask about claudication: reproducible calf, thigh or buttock pain when walking, relieved by rest.
  

• Ask if there is rest pain: pain in foot/leg while at rest, especially at night.
  

• Ask about non-healing foot wounds.
  

• Ask about symptoms of altered foot sensation, coolness, colour changes.
  

• Ask about decreased walking distance, or avoidance of walking/stairs due to leg discomfort or fatigue.
  

Physical Examination

• Palpate pulses: femoral, popliteal, dorsalis pedis, posterior tibial; note symmetry and strength.
  

• Inspect skin: hair loss, dryness, thin or shiny skin, nail changes.
  

• Check capillary refill, temperature of feet compared with non-diabetic baseline or other foot.
  

• Assess for foot deformities or callus formation.
  

• Neuropathy screen (monofilament or tuning fork) helps distinguish neuropathic causes from vascular causes; both often co-exist.
  

Objective Tests Available in Primary Care (or by Referral)

1.Ankle-Brachial Index (ABI)

When to use: Patients with symptoms/signs or high risk

Interpretation (Key Cutoffs):

≤0.90 = PAD; 0.91–0.99 borderline;

≥1.40 suggests non-compressible arteries

Limitations in Diabetes:

Medical calcification may falsely elevate ABI in diabetics.

2.Toe-Brachial Index (TBI) / Toe pressures

When to use: When ABI is unreliable, or ulcer present

Interpretation (Key Cutoffs):

TBI <0.70 (thresholds vary) = likely impaired perfusion; low toe pressure suggests poor healing

Limitations in Diabetes:

Toe measurement may require special equipment.

3.Duplex Ultrasound (arterial Doppler)

When to use: Localisation of disease, monitoring, when non-invasive imaging available

Interpretation (Key Cutoffs):

Visualisation of stenosis, flow velocities

Limitations in Diabetes:

Requires skilled operator, equipment availability.

4.Duplex Ultrasound (arterial Doppler)

When to use: To assess wound healing potential, in specialist centres

Interpretation (Key Cutoffs):

TcPO₂ <25 mmHg suggests poor healing prospects

Limitations in Diabetes:

Less accessible in rural or small clinic settings.

Practical Workflow for PCPs in Mauritius

1. Annual foot-vascular review in all diabetic patients: history, pulses, skin exam, neuropathy screening.
   

2. Identify high-risk patients (as above) even if asymptomatic.
   

3. If symptoms or signs present, measure ABI if feasible. If ABI is >1.30 or non-compressible, or equipment unavailable, consider referral for toe pressure / Doppler or specialist vascular assessment.
   

4. If foot ulcer/wound present, assess perfusion (toe pressure or TcPO₂ if available), manage wound, refer early.
   

5. Concurrently optimize modifiable risks: smoking cessation, blood pressure control, lipid management, glycaemic control, antiplatelet therapy if indicated.

What Local Data & Protocols Tell Us

• Mauritius already has a Diabetic Vascular Centre and expanded diabetic foot care services. World Health Organization
  

• The incidence of lower-limb amputations in diabetics remains high (403 new cases in 2022), indicating that screening and early detection can be improved. World Health Organization
  

• Research in India (which has similar burdens of diabetes, resource constraints, vascular risk) shows PAD prevalence among type 2 diabetics ~18% in many states, when using ABI with Doppler. ScienceDirect
  
  

Key Red Flags: When to Refer Immediately

• Rest pain or ischemic rest pain (pain at rest in foot / toes, worse at night)
  

• Non-healing ulcer or gangrene despite standard wound care
  

• Critical limb threatening ischemia (CLTI) features (rest pain, tissue loss)

• ABI or toe pressure indicating severely reduced perfusion, or rapid deterioration

  
  

Summary

Peripheral artery disease in diabetic patients tends to be under-diagnosed, especially when symptoms are mild or masked by neuropathy. Primary care physicians are in a unique position to pick up early signs and prevent severe complications. By combining careful history taking, physical exam, and appropriate use of ABI / toe pressure / Doppler, PCPs can greatly reduce the risk of ulcers, amputations, and systemic cardiovascular events.