Ámbitos de consideración para el estudio del clima social

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CHAPTER FIVE

5.5. DISCUSSION, CONCLUSION AND RECOMMENDATION 5.6. DISCUSSION

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significantly related to duration of DM > 5 years, low HDL and high LDL and that abnormal VPT (PN) is significantly associated with long duration of DM, high BMI and high TG.

i) Long Duration of DM: This was significantly associated with both abnormal ABI (PAD) and abnormal VPT (PN) in this study, this is in conformity with other studies reported from our environment^{63 88 89}. This is because both abnormal VPT (PN) and abnormal ABI (PAD) which are common risk factors for DFU result after a long DM duration. However, a study done on diabetic foot among Nigerians reported no significant difference in duration of DM among its study subjects with and without foot ulcer⁶⁰.

ii) Prevalence of PAD: This is considered to be single most important factor related to the outcome of diabetic foot ulcer⁹⁰. PAD may delay or prevent ulcer healing and may also interact with severe distal forefoot infection to cause abrupt digital artery thrombosis and gangrene of the toes.⁵⁷

The prevalence of PAD as defined by ABI of ≤ 0.9 was found to be 22.6% in this study. This prevalence is lower than the prevalence reported from Nigerian study which range from 54% to 65.5%60, 63 ,65, 87 and also lower than another Nigerian study that reported a prevalence of 40%⁹¹. This difference may be due to the diagnostic criteria used or difference in the age of the study groups.

It is also lower than the prevalence reported from other western countries^{60, 92,}

93.This may in turn be due to the differences in the risk factors for PAD which is generally said to be higher in the western countries probably because of their life style and perhaps cigarette smoking habit which is significantly associated with PAD and DFU⁴³.

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This low prevalence is however, similar to the prevalence reported from other African countries (Tanzania 12.5%, Sudan 10%)⁹² probably because of similar subjects demographic characteristics.

iii) Prevalence of peripheral neuropathy: The prevalence of PN in the study was found to be 42%. This prevalence is similar to the study done in persons with DM in Nigerian University teaching hospital that reported prevalence of 37%⁹¹ and also similar to that reported from Sudan (37%) but higher than that of India (27.5%) and Tanzania (28.1%)⁹².The prevalence is however lower than previous other reports from this environment which ranged from 68-100%60,63,65,87 and also lower than that of study from Europe which reported a prevalence of 86%.⁹⁴

The variation in the reported prevalence of peripheral neuropathy probably results from the differences in the diagnostic criteria and instruments used to detect peripheral neuropathy. The higher prevalence of peripheral neuropathy in this study affirms that peripheral somatic sensory neuropathy contributes up to 90% or more of DFU⁵⁷ and also to the fact that it is the commonest long term complication of DM⁶⁰. Thus, being able to detect peripheral neuropathy using biothesiometer in people with DM is probably the most important first step towards preventing DFU and lower limb amputations. The ADA recommends that all patients with DM should be screened for peripheral neuropathy at diagnosis of T2DM (and 5 years after diagnosis of T1DM) and at least annually by examining sensory functions in the feet and checking ankle reflexes. A history of neuropathic symptom should be elicited, and a careful clinical examination of the feet and lower limbs performed. One or more of the

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following can be used to assess sensory function: pinprick, temperature and vibration perception (using 128HZ tuning fork), or pressure sensation (using a 10g monofilament at the distal halluces)⁷³.

The 10g semmes-weinstein monofilament is a simple, effective and inexpensive screening device that was shown to be more sensitive (100%) though less specific (77.7%), in identifying patients at risk for foot ulceration compared to biothesiometer. (78.6% and 93.4% respectively). However, biothesiometer was favoured in this study over 10g semmes-weinstein monofilament because of its advantage to detect subclinical neuropathy⁹⁵. iv) Foot wear habit: 64.8% (227 subjects) of the diabetic study subject used

inappropriate foot wear (slippers/slip on type of foot wear and high heels) while 35.2% (123 subjects) of the diabetic study subjects had proper foot wear (canvas and lace up shoes) at the time of examination. However none of the diabetic subjects was seen without footwear at the time of examination.

This is in contrast with a widely held notion that walking bare foot is a common practice in Africa²⁴ Nigeria inclusive. This contrast may probably be due to improved education, social and economic status of the people over the time period, or may reflect different foot wearing habit of the subjects within and outside their home environment.

v) Knowledge of foot care: This study showed that 63.4% (222 subjects) of the diabetic study subject had good knowledge of foot care while only about 36.6% (128 subjects) of the diabetic study subjects had poor knowledge of foot care. The findings of this study is similar to the study done in Pakistan which showed 69.3% of the respondents had either good or satisfactory

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knowledge of foot care⁹⁶ but this study differs from that of Chennai, which showed only 33% of the patients obtained good scores (>50%) on knowledge regarding foot care⁹⁷ and various other studies from Nigeria and Iran which also showed poor awareness regarding foot care^98,99.Thus, the level of awareness on good self-care practices is higher in this study population compared to some other Nigerian studies and studies from other developing countries. The possible reasons for the greater knowledge, awareness and health behaviours could be many. Important among them could be the fact that the community health program (diabetic association) has been giving multiple specific inputs to this cohort of diabetics being followed up in the hospital. The very participation of these patients in this focused diabetes care program could influence awareness, attitudes and behaviour. Since this is a hospital-based study, the level of knowledge and practices do not reflect those of the community (diabetic association). Nevertheless, the level of awareness is much higher compared to other hospital-based studies in Nigeria indicating that health education session, motivational counseling services, and good quality care provided to them as part of the program has influenced their awareness and behaviours.

vi) Dyslipidaemia: In this study, 79.7% of the diabetic study subject had HDL cholesterol (< 1.2mmol/L), 51.7% of the diabetic study subject had high LDL cholesterol (> 2.5mmol/L) and 24.6% of the study subjects had high TG (>

1.7mmol/L), these values are not within the ADA/WHO recommended limits.

The findings in this study confirms that dyslipidaemia is a well-known risk factor for PAD in conformity with other studies^43,44,93. However, the finding of

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this study differs from other studies done in our environment⁸⁹ which showed the values of the lipid profile within ADA recommended limits suggesting that plasma lipids are not predictive of the risk of developing foot lesions in Nigerian patients with DM.

vii) Albumin to creatinine ratio (A/C): In this study 35.4% of the diabetic study subjects had abnormal A/C ratio (i.e. males > 2.5 and females > 3.5).

An increased A/C ratio is the earliest sign of DM nephropathy. An increased risk of developing DFUs with diabetic nephropathy was detected by American Diabetes Association Consensus group. This group also showed an increased risk of non-vascular DFUs including 40% of patients with chronic renal failure¹⁰⁰. Other studies also showed nephropathy to be an independent risk factor in diabetic foot patients^101,102.

viii) Glyceamic control: In this study all the glycaemic indices of the subjects (FPG, 2hpp and HbA1C) are higher than the WHO/ADA recommended glycaemic control goals⁷³. This is in keeping with other studies done in this environment60,63,65,87.Furthermore, the degree of derangement of the glycaemic indices is higher in those with abnormal VPT compared to those with abnormal ABI contributing probably to higher prevalence of subjects with abnormal VPT (neuropathy) compared to abnormal ABI (PAD) although the degree of poor glycaemic control did not attain statistical significance.