Antidiabetic pills — an overview
Dr K.P. Singh

Type-2 diabetes (formerly called adult-onset diabetes) is a disorder characterised by high blood glucose in the context of insulin resistance and relative insulin deficiency. Goals for effective management of type-2 diabetic patients are related to effective control of blood glucose, blood pressure and lipids to minimise the risk of long-term consequences associated with diabetes. Though exercise and dietary management (lifestyle modifications) provide the basis for metabolic control of patients with type-2 DM, over a period of time this approach alone is insufficient to attain glycemic targets, calling for the introduction of anti-hyperglycaemic therapy. But it must be pointed out that continuing lifestyle modification is a vital prerequisite to guarantee target blood glucose levels and reduce cardiovascular risk.

Several groups of drugs, given orally, are effective in Type-2 DM. These drugs include various classes of oral antidiabetic drugs (OAD) like Alpha-glucosidase inhibitors, Insulin Secretagogues (agents which increase the amount of insulin secreted by the pancreas), insulin sensitizers (they increase the sensitivity of target organs to insulin) and dipeptidyl peptidase-4(DPP-4) inhibitors. The numbers of the available OADs have increased significantly in the last decade, translating into more therapeutic options.

Though not technically hypoglycemic agents, Alpha-glucosidase inhibitors slow down the digestion of carbohydrates in the small intestine, reducing or slowing the amount of glucose absorbed in the bloodstream. Though effective as monotherapy only in the initial stages of impaired glucose tolerance, they can be effective in a combination with other agents in the management of type-2 diabetes.

Inhibitors of DPP-4 (type of protein) are a class of OADs that block DPP-4 step, which plays a major role in glucose metabolism. It is responsible for the degradation of incretins such as glucagon-like peptide-1 (GLP-1). They act by increasing blood concentration of the GLP-1 by inhibiting their degradation by DPP-4. This, in turn, decreases blood glucose but, more significantly, increases insulin secretion and decreases gastric emptying. Presently available DPP-4 inhibitors are Vildagliptin and Sitagliptin.

Adverse effects of oral antidiabetic drugs

Insulin sensitizers — Pioglitazone and rosiglitazone are the two agents in clinical use. The major side-effects of rosiglitazone and pioglitazone are weight gain, fluid retention and fractures. These drugs should be avoided in active liver disease and heart failure.

Sulfonylureas — Glimepiride, glipizide and glibenclamide are agents in clinical use. They may produce hypoglycaemia, severe enough to produce hypoglycaemic coma (rarely). This class of drugs should be avoided in active liver disease.

Alpha glucosidase inhibitors — Acarbose, miglitol and voglibose are in common use and may produce flatulence and diarrhoea.

Metformin — Weight loss and abdominal pain are the common adverse effects. And very rarely is lactic acidosis seen which is a serious condition. Metformin should not be used in patients with kidney dysfunction and failure. It should also not be taken with simultaneous use of radio-contrast.

These oral antidiabetic tablets must never be used during pregnancy. These should also be avoided in type 1 diabetes.

The writer is Senior Consultant, Endocrinology, Fortis Hospital, Mohali, and can be contacted at k.singh@fortishealthcare.com

Gums — a boon for diabetes, cholesterol management
Dr Jaspreet Singh and Dr Lovedeep Kaur

Plant-derived gums are excellent stabilising and thickening agents, and are traditionally used for many food applications. There is a steady rise in the use of gums in the processed food products because of the rapid increase in the consumption of ready-made meals and novelty foods.

Some of the commonly used food gums are locust bean (or carob), gum arabic, guar gum and cassia gum, and most of them are grown or available in India.

A commercial gum may contain around 75-80 per cent soluble fibre, 5-7 per cent insoluble fibre, 2 per cent crude protein, 0-1 per cent total lipids, 7-10 per cent moisture, and 0.5-0.8 per cent of ash (minerals). Most of the gums are generally recognised as safe for use in food products.

An increased amount of dietary fibre and low quantity of fat and sugar are required in the diet due to our modern life styles and prevalence of diseases such as diabetes and hypercholesterolemia.

Diabetes mellitus is a metabolic disorder marked by chronic hyperglycemia and has harmful effects on the vital organs. The diets containing large amounts of rapidly available carbohydrates (such as starch) raise the blood glucose and insulin responses immediately and could have detrimental effects on the health.

In many countries, gums are now regarded as a soluble fibre and have also been used as fat replacers in low-calorie food products. During digestion, the soluble dietary fibre of gum acts like a sponge and absorbs water in the human intestine; mixes the food into gel and thereby slows down the rate of digestion and absorption of carbohydrates, which lowers postprandial blood glucose levels.

Gums, due to their viscous nature, slow down the gastric emptying, which generates a feeling of fullness and suppresses appetite. Therefore, it leads to a satiety-promoting effect and ultimately weight loss. The presence of gums thickens the intestinal contents that delay glucose absorption, resulting in a decrease in blood sugar spikes following a meal. Gums have also been reported to lower blood cholesterol levels (both total and low-density lipoprotein cholesterol, LDL-c) and prevent hypercholesterolemia with a decreased risk of coronary heart disease (CHD).

A study based on rat experiments proved that consuming traditional wheat flour chapattis containing guar gum and legumes had a significant cholesterol-lowering effect.

Enteral nutrition has become more popular during the last two decades in post-operative patients and as a supplement in artificial nutrition. The gums also play an important role in the preparation of therapeutic enteral diets. The formulation of enteral feeds with soluble dietary fibre in the form of gums can help overcome constipation and maintaining a health microflora in the large bowel in post-operative patients.

The writers are research scientists at Massey University, New Zealand. Email:j.x.singh@massey.ac.nz.

Muscle strengthening helps in low back pain
Dr Ravinder Chadha

People suffering from back pain normally take medicines and prefer rest for a prolonged period. There is no doubt that pain in the low back decreases, but the muscles supporting the back start getting weak. Such patients may get relief from the pain but will always complain of back pain/stiffness on prolonged sitting/standing as the shock absorption capacity of muscles controlling the spine decreases. Aging also adds to disability as muscles become less flexible and weak. Inadequate strength of the back muscles increases the risk of low back pain.

Muscles of the back, abdomen and buttocks support the spine, and strong abdominal muscles are more important than strong back muscles in order to support lower back and prevent low back pain.

Strong and flexible muscles enable an individual to maintain the correct posture. The spine is bestowed with the capacity for a natural inward curve at the lower back. A neutral spine distributes the load equally throughout the lower back. This helps in the prevention of injury and facilitates efficient mobility.

Movements of the back are a combination of the forward, backward and rotational movements. These movements entail coordinated action of different muscles — forward bending requires rectus abdominis, internal and external oblique and hip flexor muscles to act in tandem.

Healthy functioning of the low back does not depend on muscle strength and flexibility alone.

It also depends on the coordination of movements involving the lower back. Those who move clumsily put undue strains on their low back muscles and spine. Back-strengthening exercises would be an ideal preventive. However, it’s difficult to determine which back-muscle strengthening programme is the right option. There is no doubt that low back exercises vary with each individual keeping in view the curvature/alignment of the spine, obesity, the muscles controlling the spine, etc. The basic principle that should be kept in mind is that any exercise which aggravates pain should be stopped immediately. Secondly, exercises should be done after a proper warm-up and under proper guidance.

EXERCISES

• Sit-ups — Lying on the back with knees flexed, feet on the floor, and arms across the chest, slowly get up in an upward direction. Return back. Repeat 10 to 15 times.
• Knee-elbow touches — Starting in an upright standing position, lift the right knee and touch with the left elbow by rotating the trunk. Returning to the standing position, repeat with the other knee and elbow.
• Balancing exercise — Starting on all fours, keeping the lower back straight, extend the left leg straight back and the right arm straight ahead while remaining in balance on the right knee and left hand. Repeat with the opposite arm/leg around up to 10 times.
• Bridging — Lying with the face downwards resting on the elbows. Go up on the toes forming a bridge from the feet to the elbows. Low back should be straight holding for a count of 10 to 15.
• Reverse crunch. Lying on the floor with knees bent and hands by the side head. Using only stomach, lift up the legs so that the hips are lifted off the floor. Lower the hips and lift again just prior to it, resting on the floor again. If you suffer from low back pain, improving the muscle strength is the only way to avoid its recurrence.

The writer runs a pain management clinic in Chandigarh.
E-mail:- chadha_r2003@yahoo.co.in