Diabetes Mellitus Case Study Biology Essay

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Claire is a 42 year old female, with type 2 diabetes Mellitus. Claire has a medical history of hypertension and mild renal impairment. Claire is concerned about her thick yellow crumbling toenails that affects over eighty percent of each nails on both feet, and has been presented for many years. Claire wants to her toenails to look normal. In this essay I will discuss the pathology around patient's presentation, propose at least four differential diagnoses, a provisional diagnosis and the subsequent ongoing management of their Diabetes Mellitus type 2. I will then examine what type of test clinician should order to make a proper diagnosis. I will then discuss and interpret the results of full blood count, cholesterol level check, Creatinine levels, 20% KOH, Gram Staining, and Lacto phenol. Claire is taking a lot of different medications. These medication are Metformin 500mg, Glibenclamide 5mg, Accupril 40mg, Probiotics (three tablets daily), St John Wart (one tablet daily), Thompson's Immunoforte (once daily), Garlic capsule (3 capsules daily), 2mL of Echinacea with water (3 times daily).


"Diabetes is a disease characterised by elevated blood glucose levels. It is an increasing global burden for healthcare systems, and it is estimated that about 7% of adults worldwide have the disease" 200,000 people in NZ with diabetes Ministry of Health, (2010). Approximately 85 to 90% of New Zealanders with diabetes have type 2 diabetes (New Zealand Guidelines Group. (2003). (Robert G. Frykberg, 2000) Describes Diabetes Mellitus type 2 as a metabolic disorder resulting from the body's inability to produce or utilize insulin. Type 2 Diabetes Mellitus can be caused by lack of exercise, heredity, obesity, alcohol and smoking Merck Manual, (2007)

Diabetes Mellitus type 2 is more common in Maori and Pacific Islanders then European New Zealanders Diabetes New Zealand, (2008)People with diabetes mellitus type 2 sometimes develop nerve damage to the feet can cause the lining of the blood vessels to become thickened. This can lead to hypertension. This is because thickened blood vessels significant inadequate blood flow to lower extremities. This causes hypoxia (lack of adequate oxygen at the tissue level) TOTARA (2003). One of the most serious is that either the whole, or part, of your feet can become numb or insensitive to pain Diabetes New Zealand, (2008). 

In relation to Podiatric management of the foot, taking history of the patient is very important. Other things we can do is to examine an Direct visual inspections, assess for peripheral neuropathy using either 10 g monofilaments or biothesiometer, and assess peripheral circulation, peripheral arterial disease, previous amputation, previous ulceration (risk of recurrent ulcer) or current ulceration (risk of amputation), structural foot deformity and plantar callus. (New Zealand Guidelines Group. (2003). Thorough assessment and management of the foot health status of a person with diabetes requires investigations within the categories dermatological (skin lesions), vascular (pulses), neurological (sensation), biomechanical (including pressure and gait), morphological, footwear and education (on how to control their diabetes) Edmonds, E, M., Foster, VM, A (2002)

We can check Claire blood circulation on her feet by doing an ankle brachial index (ABI). We will take a systolic reading of the brachial artery of both arms by using a stethoscope and systolic reading of posterior tibial and dorsalis pedis artery both feet using 8 Hz Doppler. By taking the highest the reading of brachial artery systolic reading and highest reading from posterior tibial artery and dorsalis pedis. By using an ABI= ankle/brachial the normal range should be between 0.9-1.2. If numbers are higher or lower than that it means that, Claire might have intermittent claudication Doobay, V, A and Anand, S, S, (2005)

Diabetic neuropathy leads to progressive lower-limb muscle atrophy, loss of sensation, central, peripheral and autonomic nervous systems and gait alterations that overload feet New Zealand Guidelines Group. (2003). The most common onset of diabetic degeneration is the loss of sensory function (heat pressure and fine touch), moreover motor neuropathy is also prevalent affecting the lower limb musculature and contractile capability muscles which are primary for normal biomechanical function. In addition, autonomic neuropathy causes degeneration in sympathetic and parasympathetic nervous systems causing decreased sweat production and increased collagen glycation leading to a severe reduction in join mobility. The progression of these co-morbidities can lead to ulceration in areas of high plantar pressures (New Zealand Guidelines Group. (2003)

Diabetes can cause renal impairment (nephropathy). "Nephropathy is characterized by thickening of the glomerular basement membrane, mesangial expansion, and glomerular sclerosis". These changes can cause glomerular hypertension and slowly declines in Glomerual filtration rate National Kidney and urologic Diseases Information clearinghouse (n.d.). "Hypertension, is a major factor in the development of kidney problems in people with diabetes." Kathleen, D. (2010) Family history of hypertension and the presence of hypertension appear to increase chances of developing kidney disease. Hypertension also accelerates the progress of kidney disease when it already exists. Edmonds, E, M., Foster, VM, A (2002)

"The ADA and the National Heart, Lung, and Blood Institute recommend that people with diabetes keep their blood pressure below 130/80." Kathleen, D. (2010),

Hypertension can be a cause of kidney disease. Kidney disease can be progresses, due to physical and chemical changes in the kidney, which can lead to increased blood pressure. Hypertension can be treated in early stages are essential for people with diabetes. Doobay, V, A and Anand, S, S, (2005)

Differential Diagnoses


onychogryphosis is referred to thickening of the nail plate, which appears "ram's horn-like" Cohen PR, Scher RK. Aging. Hordinsky MK, Sawaya ME and Scher RK. (2000). Onychogryphosis mainly involves the hallux toenail. Onychogryphosis appears uneven, thickened and discolouration (brownish and yellowish). Onychogryphosis is mainly due to irregular cutting of the nails, trauma and improper footwear reference. The cause of onychogryphosis is that nail plate grows upwards and therefore deviates laterally towards the second digit Turner, A, W and Merriman, M, L. (2005). The direction of the nail growth is being influenced by pressure from footwear or site of trauma on the matrix. In a research it showed us that "A few patients develop subungual gangrene due to pressure effects, especially in the presence of diabetes mellitus or peripheral vascular disease." Singh, G., Haneef, S, N and A, U. (2005). Onychogryphosis can be mistaken for Onychomycosis because they both have same type of discolouration and they both cause the nails to be thickened.


Onychauxis nail is thickening of the nail Dermnet. N,d.. Onychauxis can be caused by trauma, tight shoes. Onychauxis nails are mainly found in elderly population. Onychauxis is characterised as hyperkeratosis, discolouration, and loss of nail plate. Onychauxis can cause pain on the nail bed, this is due to thickened nail and getting pressure from the shoes Turner, A, W and Merriman, M, L. (2005). Due to pain and pressure can be cause Onycholysis, subungual haemorrhage and increased susceptibility for Onychomycosis. Anirudh, M. (2011)


Onycholysis is a nail disorder. Onycholysis can be "Endogenous, exogenous, hereditary, and idiopathic factors can cause onycholysis. Contact irritants, trauma, and moisture are the most common causes of onycholysis, but other associations exist." Hecker, S, M. (2010). .Onycholysis is characterised by separation of the nail plate from the distal free margin and progresses proximally. In Onycholysis, the nail plate is separated from the nail bed. Onycholysis is usually characterised as smooth, firm, and dry. Onycholysis is always gets mixed up with Onychomycosis because they both have same presentation Hsu, LM, M. (2002). The presentations are nail discoloration may appear underneath the nail as a result of infection DermNet New Zealand (n.d.).

Yellow Nail Syndrome

"Yellow nail syndrome (YNS) is a rare disorder characterized by a triad of yellow discoloration and destructive changes of nails, lymph oedema and a variety of pathologies in the respiratory system" Singh, G., Haneef, S, N and A, U. (2005) The yellow nail syndrome is common in females (1:2) and occurs mainly in middle age woman Reference. In yellow nail syndrome they become yellowish- green colour, they also can appear thickened and display an increased longitudinal curvature with some evidence of Onycholysis. Claire cannot have yellow nail syndrome because yellow nail syndrome is cause by systemic disease ie, respiratory disease. Ahmed, E, M and Eltinay F. (2009)


Onychomycosis affects approximately 5% of the population worldwide (Indian journal). The rate of onychomycosis increases with age as 15% to 20% of the population from 40 to 60 years of age, and 32% of the population from 60 to 70 years of age is diagnosed with the condition (Scherer. W., McCreary. J., and Hayes. W. 2001). The reasons for the age related increase in onychomycosis can be due to diabetes, longer exposure to pathogenic fungi, inactivity or the inability to cut toenails or maintain good foot care, repeated nail trauma and poor peripheral circulation Elewski ,B. (1998). Onychomycosis is defined as an infection of the nails by a fungal element and it represents approximately 18 to 40 % of all major onychopathies and about 39% of all superficial mycotic infections (Godoy, P., Nunes, F., Silva, V., Tomimori-Yamashita, J., Zaror, L., & Fischman, O. 2004).

Onychomycosis is often thought of as a cosmetic problem, however it has a great impact on the overall well being of the patients health (William P. Scherer, 2001). Onychomycosis is really hard to differentiate from Oncycholysis, because they both have same clinical features, e.g. same brownish colour. The most common clinical features of Onychomycosis include discoloration of the nail plate, hyperkeratosis and brittle nails. Onychomycosis represents a common and complex medical problem. (Arrese. J., Franchimunt. C., and Pierard .G 1999). In the past onychomycosis was referred to a nondermatophytic infection of the nail, but it is now used as a general term to denote any fungal nail infection. Elewski ,B. (1998).

Analysis and Interpret Results (Laboratory Investigation)

Gram Staining

Gram staining method is used to differentiating bacteria species in to Gram- positive and Gram- negative. The bacteria divide in these two groups are based on the chemical and physical properties of their cell wall. By doing this test we can see what kind of bacterial infection is in Claire toenails. After doing Gram staining we can look under microscope to figure out if the bacterial infection is Gram Positive or Gram Negative Gregersen, T. (1978). Bacteria that retain the gentian violet dye appears blue/black when observed under microscope it mean the bacterial infection is gram positive. This is because gram positive bacteria have a high lipid cell wall. And if we see red colouration on the cell wall then its means the bacteria infection is gram positive. Rao, S. (n.d)


KOH Testing is a very easy test which can be done in a clinic. The KOH 20% (potassium hydroxide) test is conducted to identify what type of fungus is implicated in presentation of Onychomycosis in this patient Gregersen, T. (1978). Scrapings were put onto a clean glass slide and heated (not boiled). Then 20% KOH will be added to help dissolve the keratin so that it is easy to identify under direct microscopy. When looking under the microscope if we see hyphae or strands pollen it means the infection is fungal. Gregersen, T. (1978)


The lacto-phenol cotton blue is a mounting medium used in microbiology laboratories, primarily for preparing mounts of fungal cultures. Lacto-phenol cotton blue was added to enhance microscopy. The sample was then examined under direct microscopy. Is a tool we can use to determine if the nail sample contains any fungal elements.

Complete blood count

I will tell Claire to get a full blood test because from this we can see if Claire is taking care of diabetes and to check if Claire has any infection in the body. Red blood cells (which carry oxygen) White blood cells (which fight infection), Haemoglobin, (the oxygen-carrying protein in red blood cells), Hematocrit (the proportion of red blood cells to the fluid component, or plasma, in your blood), Platelets (which help with blood clotting) Ohio Health, Believe in we. (2011). We will do this test on Claire just to see her overall health and from this we might found something which she may not know about i.e. anaemia. Complete blood count will allow to diagnose her renal impairment and to monitor her renal impairment Diabetes New Zealand. (2010). "Abnormal increases or decreases in cell counts as revealed in a complete blood count may indicate that you have an underlying medical condition that calls for further evaluation." Ohio Health, Believe in we. (2011)

Creatinine level

Creatinine level is a test to "measures how efficiently the kidneys remove Creatinine and other wastes from the blood. Low Creatinine clearance indicates impaired kidney function" Kidney Health Australia. (2011). We will do a Creatinine level check on Claire to check how good or bad Claire renal function is working. This test will allow us to see Creatinine level in the blood, which can rise due to poor clearance of Creatinine by kidney. An abnormal high level of Creatinine in the blood warns us of possible malfunction or failure of the kidneys MedicineNet. (n.d). So therefore a standard blood test will be required regularly to check the amount of Creatinine level in the blood. The normal range for Creatinine level for women is 0.5 to 1.1 mg/dL (38.1-83.9µmol/l) Diabetes Explained (n.d.)

Cholesterol level

Cholesterol is a fat which can usually build up in the arteries. there are two types of cholesterol A person with diabetes has higher levels of 'bad' low density lipid (LDL) cholesterol and higher levels of triglycerides in the blood than people without diabetes Diabetes Australia. (2011). This is because diabetes can cause thickening of the arteries (atherosclerosis). People like Claire with diabetes tend to have 'bad' cholesterol particles that stick to arteries and damage their walls more easily MedicalBlog. (2010). We will do a cholesterol level check on Claire to find out how much cholesterol is her blood stream and how we can closely relate to the heart. By knowing of Claire cholesterol levels we can see if see in risk of any heart condition which can affect her in the future MedicalBlog. (2010). By having higher levels of cholesterol concentration in the blood it can make the arteries narrow and results in reduce blood flow, which may result heart condition Kidney Health Australia. (2011). Due to narrowing of the arteries it will cause cholesterol to accumulate in the arteries causing a blockade which may lead myocardial infarction or a heart attack. This is due to lack of blood flow going to the heart therefore less oxygen travelling to the heart and rest of the body. The normal cholesterol level in the blood should be less than 5mmol/l. Diabetes Australia. (2011)

Pharmacological intervention (ie. drug interaction, pharmacodynamics, safe dose)


Metformin 500mg is given to the people with Diabetes Mellitus Type 2. This is because Metformin causes an increase in peripheral uptake of glucose by increasing the efficiency of available insulin. Metformin should be careful given to the people like Claire who has renal impairment, because medsafe tells that Metformin can increase the chances of renal failure or renal dysfunction. This because Metformin is not metabolised hepatically (doesn't metabolised by liver) and excretes unchanged by the kidney. Medsafe. (2009). Garlic can cause potential hypoglycaemic effect of insulin. Garlic is frequently used in the treatment of diabetes, randomised trials were done on individuals with and without diabetes, and the studies have not demonstrated any clinically significant difference on blood glucose or insulin sensitivity Owen, J. A. (2005).

Glibenclamide 5mg

Glibenclamide is a "oral hypoglycaemic agent, acts initially on the functioning beta cells of the pancreas to release insulin." Medsafe. (2009). Glibenclamide works mainly by stimulating the cells in the pancreas that produce insulin. These cells are called beta cells. Glibenclamide causes the beta cells to produce more insulin. This helps to decrease the amount of sugar in the blood of people with type 2 diabetes

Accupril 40mg

Accupril is used to lower high blood pressure (hypertension) Medsafe. Accupril is an angiotensin-converting enzyme (ACE) inhibitor. ACE is important is convert angiotensin I to angiotensin II. This is important to vasoconstrictor blood vessels. The effects of Accupril in reducing hypertension is mainly primary by inhibiting the ACE in tissues to travel in the blood circulating system therefore reducing production of angiotensin II Medsafe. (2010).. The inhibition of production of angiotensin II can stimulate the secretion of aldosterone from the adrenal cortex, thereby facilitating renal sodium and fluid reabsorption Medsafe. (2010).. People who are taking Accupril or any ACE inhibitor are advised to not to have high diet of potassium. This because of "Reduced aldosterone secretion by Accupril may result in a small increase serum potassium." Therefore causing hyperkalemia Medsafe. (2010). Garlic has been found lower blood pressure and may theoretically potentiate the effects of hypotensive agents. There has been non clinical hypotension associated with concomitant use of garlic and antihypertensive agents. Drugs.com

Probiotics (three tablets daily)

Probiotics are: "Live microorganisms which when administered in adequate amounts confer a health benefit on the host" WHO.  People suffering from constipation, diarrhoea, yeast overgrowth and urinary tract infections may also benefit. 

St John Wart (one tablet daily)

St John's Wart is often used as an antidepressant for mild to moderate depression and a sedative (Owen, 2005). The common side effects of using St John Warts are headache, dry mouth, nausea, gastrointestinal upset and sleepiness Halushka, V. P (2009). St John warts is metabolised by the Cytochrome (CYP) enzymes. Induction of the CYP enzymes can lead to decrease in plasma levels of the drug resulting in reduce in efficacy and adverse effects. Because Claire is taking Echinacea which is another immune booster, Echinacea can decrease the function of CYP enzymes in the liver Gorski J. C et al. (2004). which may lead to toxicity of St John Warts in the body. The adverse reaction can be serious the symptoms can be lack of coordination, hyperreflexia, agitation, coma, confusion, tremor, fever, nausea and diarrhoea. Halushka, V. P (2009)

Thompson's Immunoforte (once daily)

Thompson's Immunoforte is given to the people to boost their immune system. . Thompson's Immunoforte also contains Zinc and is used as an immunostimulator and is successful for treating the common cold (Thompsons Nutrition Ltd, 2009). There are no side effects or any drug interaction with Claire's medication.

2mL of Echinacea with water (3 times daily)

Echinacea is mainly is used for the treatment of the common cold, coughs, bronchitis, influenza and inflammation of the mouth and pharynx Gorski J. C et al. 2004.. the benefit of using Echinacea is in the treatment of infection is very effective important due to its ability to stimulate the immune system. Gorski J. C et al. 2004. Echinacea can inhibit the metabolism by decreasing the function of Cytochrome P450 enzyme (CYP450). So therefore Echinacea can interact with some of the drugs which are metabolised CYP450 enzyme. The drugs which are metabolised with CYP450 can be from one of these groups' immunosuppressants, anticoagulants, calcium channel blockers and benzodizeoines Gorski J. C et al. 2004.


A topical antimycotic therapy would probably be suitable for this patient due to the superficial nature of the nail infection. Topical treatment should first be considered for the patient before surgical intervention is commenced. Because eighty percent of Claire both feet toenails are affected surgery won't be an option.

Nystatin= topical preparations are indicated in the treatment of cutaneous or mucocutaneous mycotic infections caused by Candida species

Terbinafine= Broad spectrum anti-fungal drug. At low concentrations it is fungicidal against dermatophytes, microsporum and Candida yeasts and can be fungicidal or fungistatic against yeasts, depending on the specific species.

I would recommend Nystatin because Nystatin is not absorbed into the systemic circulation from intact skin and mucous membranes. But the side effects are of this topical use of Nystatin are Local irritation and sensitisation (such as rash, dermatitis, pruritis and burning)

I wouldn't recommend Terbinafine because it is strongly bound to plasma proteins, with high drug concentrations accumulating in skin, hair and nails. There are some side effects, such as headache, upset stomach, skin rashes, or allergic reactions to ingredients in the medication. Other side effects (of a more serious nature) include: liver damage and heart failure.

For Claire I would recommend tea tree oil. Because it has no side effects, the recommended application is 100% solution topically BID x 6 months. The education we recommend using tea tree oil is that to not touch the toe nail with the liqauer tip, because if Claire touch the toenails with liquer the whole tree tea oil solution will be contaminated and the infection on the toenails will be not able to get fix.

The education advice we can give to Claire is to maintain her diabetes and her hypertension. We would tell Claire to get her blood pressure check every 3 weeks .