Page 192 Guide to Pain Management in Low-Resource Settings

180 Gaman Mohammed

He was started on insulin, antibiotics, analgesics, tion. As the disease progresses, neuronal dysfunction
and a tricyclic antidepressant and was given a thorough correlates closely with the development of vascular
education on the importance of good glucose control and abnormalities, such as capillary basement membrane
appropriate footwear. Local care was given. Yusuf re- thickening and endothelial hyperplasia (thickening),
ported decreased pain at night and improved wound-site which contribute to diminished oxygen supply and hy-
healing on his return visit to the offi ce approximately 3 poxia. Neuronal ischemia is a well-established charac-
weeks later. teristic of diabetic neuropathy. Vasodilator agents (e.g.,
angiotensin-converting-enzyme inhibitors) can lead to
What is the scope of the problem? substantial improvements in neuronal blood fl ow, with
corresponding improvements in nerve conduction ve-
Diabetes currently aff ects 246 million people world- locities. Th us, the microvascular dysfunction that oc-
wide and is expected to aff ect 380 million by 2025. curs early in diabetes parallels the progression of neu-
By 2025, the largest increases in diabetes prevalence ral dysfunction and may be suffi cient to support the
will take place in developing countries. Unfortunate- severity of structural, functional, and clinical changes
ly, these countries have economic burdens and con- observed in diabetic neuropathy. In addition, elevated
straints. More than 80% of the expenditure for medical intracellular levels of glucose lead to binding of glucose
care for diabetes is made in the world’s economically with proteins, thus altering their structure and destroy-
richest countries, and less than 20% in the middle- and ing their function. Certain of these glycosylated proteins
low-income countries, where 80% of diabetics live. Th e are implicated in the pathology of diabetic neuropathy
WHO estimates that diabetes, heart disease, and stroke and other long-term complications of diabetes.
together will cost billions of dollars, even in a low-re-
source country like Tanzania.
Are analgesics the only treatment
option in diabetic polyneuropathy?
Why is pain in patients

with diabetes an issue? Just the opposite! Glycemic control has a favorable ef-
fect on each of the microvascular complications of
In diabetic patients, neuropathy is the most common diabetes mellitus, both in preventing the onset of new
complication and greatest source of morbidity and
complications and in slowing the progression of estab-
mortality, with an estimated global prevalence of ap- lished complications. Glycemic control should be an
proximately 20%, with the highest numbers being in
important cornerstone in pain control because pain as-
African countries: Tanzania (25–32%), Zambia (31%), sociated with diabetic neuropathy decreases with im-
and South Africa (28–42%). Diabetic neuropathy is
proved glycemic control.
implicated in 50–75% of nontraumatic amputations in
African countries.
Why does it hurt even though the
Why do patients with diabetes patient does not “feel” anything, as
develop neuropathy? is typical in diabetic neuropathy ?

Th ere are four factors: Neuropathy in diabetics can present as sensory loss (in-
• Microvascular disease sensate) neuropathy or painful neuropathy. Th e major-
• Advanced glycosylated end-products ity of people have the insensate type. However, approxi-
• Protein kinase C mately 4–7% of patients with diabetes suff er chronic,
• Polyol pathway often distressing symptoms of pain (“pins and needles”)
or numbness in their feet. Why patients with diabe-

What is microvascular disease? tes may develop painful neuropathy is not fully under-
stood, although it is known that patients with poorly
Blood vessels depend on normal nerve function, and controlled diabetes for a long time are more likely to
nerves depend on adequate blood fl ow. Th e fi rst patho- get chronic painful neuropathy. Painful symptoms can
logical change in the microvasculature is vasoconstric- be transient, often lasting less than 12 months. Th ese