Hypoglycemia

Mediterranean diet and cognitive decline

A Mediterranean diet is one which comprises of fresh vegetables, fruits, beans, whole grains, nuts, olives, and olive oil along with some cheese, yogurt, fish, poultry, eggs, and wine.
A recent study has shown that this diet if adopted and followed leads to a slower decline in the cognitive function. The two main hypotheses are that it has a lot of anti-oxidants which prevent cell death in the brain and secondly it has a protective effect on the vasculature of the brain and thus prevents vascular dementia. Thus, the Mediterranean diet not only improve your looks and protects your cardiovascular system but also your brain cells benefit from it.

Highest prevalence of Diabetes Mellitus

Figures till November 2012 show that the top 5 countries with the highest prevalence of Diabetes Mellitus are from the pacific islands. They may be the smallest islands but the epidemic of diabetes is one of the worst there. More than a third of adults in some of these countries have diabetes and the combined toll of complications, deaths and loss of income make diabetes a real threat not just to the individuals experiencing the disease but also to the economies of the countries themselves.

Above is an image showing the locations of the pacific islands.

Top 10 countries with Diabetes Mellitus 2012

Data till November 2012 showed that together, these 10 countries make up 75% of the total prevalence of diabetes in the world.  Urbanisation and the accompanying changes in lifestyle are the main drivers of the epidemic in addition to changes in population structure where more people are living longer.

Anemia in diabetic patients - Erythropoietin treatment?

If you encounter a normochromic and normocytic anemia in a diabetic patient, do not forget that it may be a case of erythropoietin deficiency. This deficiency can occur early in diabetic nephropathy (well before stage 5 of chronic kidney disease).

In adults, about 85-90% of the erythropoietin comes from the kidneys and 10-15% from the liver. It is produced by interstitial cells in the peritubular capillary bed of the kidneys and by perivenous hepatocytes in the liver. In cases of decreased renal mass, the level of erythropoietin falls and does not increase much in response to hypoxia (anemia). This occurs even if the liver is normal as the latter cannot compensate for the kidney's loss of function.

Since the availability of recombinant human erythropoietin to patients in 1989, anemia and transfusion requirements have become relatively  rare in patients on hemodialysis.
After adequate treatment with erythropoietin, studies have demonstrated that there is an:
1) enhanced exercise capability, presumably partly because of improved cardiac function with reduction in ventricular hypertrophy,
2) improved quality of life with improved physical performance, work capacity and cognitive capacity,
3) improved sexual function,
4) reduced rates of hepatitis and iron overload because of fewer transfusions.

All of the erythropoietin preparations are now referred to collectively as erythropoiesis stimulating-agents (ESAs). So far, intravenous route has been the sole route of administration and is given during hemodialysis but investigations are going on about the possibility of subcutaneous administrations.

With subcutaneous administration, peak serum concentrations of about 4% to 10% of an equivalent IV dose are obtained at around 12 hours, and thereafter they decay slowly such that concentrations greater than baseline are still present at 4 days.
The bioavailability of subcutaneous epoetin is around 20% to 25%. Nevertheless, subcutaneous application
is more efficient than IV application, allowing an approximately 30% dose reduction to maintain the same hemoglobin concentration.
Presumably, the early peak concentrations of epoetin after IV injection are inefficient, but the more prolonged elevation of hormone concentrations after subcutaneous application allows a more sustained stimulation of red cells production. Thrice-weekly administration has remained the most popular dosage frequency for both IV and subcutaneous administration, although once-weekly, twice-weekly and
seven-times-weekly (once-daily) dosing have all been used.

The hemoglobin target should be in the range of 11-12 g/dL and should not be greater than 13 g/dL.

Above is a diagram showing the change in hemoglobin level (blue line) with respect to different dosage of erythropoietin from 1991 till 2009 in an attempt to keep the hemoglobin in the target range. Hemoglobin level should be tested at least once monthly. 

Thoracic cage injuries - simple and complicated

Acanthosis nigricans - cause and significance

Acanthosis nigricans is a hyperpigmented velvety lesion usually found in the neck and the axillary region. It can also be seen elsewhere e.g. the belt line, creases over the dorsal surface of fingers. The palms and soles are typically not involved.

Pathologically, it is characterized by an increased number of melanocytes associated with hyperkeratotic epidermal papillomatosis.

It is strongly associated with insulin resistance but it is a non-specific condition and can also be found in obesity, polycystic ovarian syndrome, endocrine diseases like acromegaly and Cushing's syndrome, as well as some malignant tumours.

The severity of the acanthosis nigricans correlates with the degree of insulin resistance and the level of serum insulin.
The exact mechanism of its formation is still unclear but it is speculated that there are related IGF-1 receptors in the skin which are activated by ambient hyperinsulinemia.

If the insulting factor is removed, there may be a regression of the lesion.

Below are photos of a patient requiring more than 100 IU of insulin per day and despite dieting, the level of glycemia remained high.

It is an interesting case because it is an atypical location for acanthosis nigricans. The back of neck and axilla were free of any lesions.

Classification of Diabetes Mellitus

Diabetes is divided into 4 different classes:

1) Type 1 diabetes (results from beta-cell destruction, usually leading to absolute insulin deficiency)
2) Type 2 diabetes (results from a progressive insulin secretory defect on the background of insulin resistance)
3) Other specific types of diabetes due to other causes, e.g. genetic defects in beta-cell function, genetic defects in insulin action, diseases of the exocrine pancreas (such as cystic fibrosis, pancreatitis) and
drug- or chemical-induced (such as in the treatment of HIV/AIDS or after organ transplantation)
4) Gestational diabetes mellitus (GDM) (diabetes diagnosed for the first time during pregnancy that is not clearly overt diabetes).

Respiratory failure - Definition, classification and difference between acute and chronic type

Respiratory failure may be classified as hypercapnic or hypoxemic.
Hypercapnic respiratory failure is defined as an arterial PCO2 (PaCO2 ) greater than 45mmHg.
Hypoxemic respiratory failure is defined as an arterial PO2 (PaO2 ) less than 55 mmHg when the fraction of oxygen in inspired air (FiO2) is 0.60 or greater.
In many cases, hypercapnic and hypoxemic respiratory failure coexist.

Distinctions between acute and chronic respiratory failure are summarized in the table below.

In general, acute hypercapnic respiratory failure is defined as a PaCO2 greater than 45 mmHg with accompanying acidemia (pH less than 7.30). The physiological effect of a sudden increase in PaCO2
depends on the prevailing level of serum bicarbonate anion. In patients with chronic hypercapnic respiratory failure e.g. COPD, a long-standing increase in PaCO2 results in renal compensation and an increased serum bicarbonate concentration. A superimposed acute increase in PaCO2 has a less dramatic effect than does a comparable increase in a patient with a normal bicarbonate level.


Distinction between acute and chronic hypoxemic respiratory failure may not be readily made on the basis of arterial blood gas values only. The presence of markers of chronic hypoxemia (e.g., polycythemia or cor pulmonale) provides clues to a long-standing disorder, whereas abrupt changes in mental status suggest an acute event.

May-Thurner syndrome

As seen in the diagram above, the left common iliac vein is predisposed to be compressed by the right common iliac artery. This can lead to stasis and eventually causing thrombosis. Another effect is that the pulsatile nature of the artery over the vein leads to turbulence in the blood flow, thereby favouring thrombosis. 

Because of this anatomical predisposition, most Deep Vein Thrombosis (DVT) seen during pregnancy occur in the left iliac vein system. All the classic investigations done for cases of DVT should be performed here also.