Motoring

Health Dr Rod Pearce

Some words in medicine give a clue as to what a doctor might be describing. If a name ends in “itis”, the diagnosis is probably an infection, swelling such as tonsillitis, or an appendicitis. Sclerosis, on the other hand, refers to a hardening of tissue, or scarring or thickening. Multiple sclerosis is the hardening and scarring of nerves and nervous tissue. Arterial hardening refers to thickening or scarring of the arteries (arteriosclerosis). Through arteries, the heart distributes blood throughout the body. So, any hardening of the arteries will affect the ability of the heart to get adequate blood (with oxygen and nutrition) to any part of the body. A poor blood supply to the brain, the heart or the legs can lead to a stroke, a heart attack or gangrene and amputation respectively. If the arteries are damaged all around the body, the condition is said to be an “arterio-path”. This condition is commonly in people who smoke. The hardening is usually divided into three types: • The inner layer of the artery – damaged by the build-up of cholesterol. This is “atherosclerosis” but, because it is the most common form of artery hardening, the terms arteriosclerosis and atherosclerosis are frequently used interchangeably. • The middle layer – hardening involves the destruction of muscle and elastic fibres and the formation of calcium deposits. This makes it possible to estimate artery damage by seeing calcium on X-rays or CT scans. • The smaller arteries (arterioles) – arteriolar sclerosis. All three forms might be present in the same patient, but in different blood vessels. A doctor working at preventing someone from having a heart attack usually thinks of any and every disease which might stop hardening of the arteries to the heart. By preventing that hardening, the rest of the body is usually protected. Smoking was years ago identified as the worst thing that could happen to arteries. It speeds up the natural hardening. And other diseases make that situation worse. If you have high blood pressure, the arteries will crack more often, repair badly if you smoke, harden quicker, and lead to an early heart attack. Every time the arteries are damaged, cholesterol will build up on the inside of the arteries quicker and make a heart attack worse – if you already suffer high cholesterol. And, if you have diabetes, the high sugar makes all that worse. It is a bit like worrying about your car rusting. The worst thing you could do is to leave it outside, uncovered, on the sand, by the sea. If you have high cholesterol, diabetes and hypertension, you are in trouble. And, if you smoke, the problems are multiplied. We know that cholesterol mends arteries and keeps them soft and pliable. We know that good cholesterol maintains the arteries in good shape

and can even reverse damage (after, say, a heart attack) if there is a higher proportion of good compared to bad cholesterol. To estimate your risk of cholesterol damage (hardening of the arteries), the usual tests are of total cholesterol (TC) and the amounts of good cholesterol (HDL) and bad cholesterol (LDL). Diabetes and raised glucose also predict early hardening. Hypertension remains a lethal problem, essentially increasing the risk of a blood vessel (artery) rupture and bleed just from the pressure effect. If someone has a stroke because of arteriosclerosis, it is assumed there is a parallel risk of heart attack and kidney disease. With smoking and diabetes, the amputation of gangrenous toes, feet and limbs is the visible sign of hardening of the arteries. With oxygen unable to get to the distal limbs and digits, gangrenous material has to be removed to stop infection and death. This is known as peripheral vascular disease (PVD). Just as PVD affects the legs (in men) it is likely to affect the penis through erectile dysfunction. A group of diseases which cause hardening and tightening of skin and connective tissues (scleroderma) is thought to be an immune system abnormality. It causes collagen build-up in the blood vessels (arteriolar sclerosis) causing further damage to tissue.

Motoring Jim Barnett

Model Nissan Qashqai ST+. Price $31,990 plus on-road costs. Engine 2.0-litre four-cylinder petrol 106kW/ 200Nm. Transmission CVT with seven-step manual mode. Safety Six airbags, emergency braking, lane departure, reverse camera, front and rear parking sensors, daytime LED running lights, blind-spot monitoring. Fuel 65-litre tank, 91 RON petrol, 6.9 litres/100km (combined test). Seating Five seats, 60/40 split-fold rear seat.

DESIGN AND FUNCTION

Hybrid cars make perfect sense in Australia – for now at least. They solve the current issues that full electronic vehicles face, such as range and limited recharging infrastructure. Toyota has set out to offer hybrids across its entire range. The all-new fifth-generation RAV4 has a hybrid variant in each equipment grade for just $2,500 extra. Six hybrid variants (2WD and AWD) are available, each using less fuel but with more power than its equivalent petrol sibling. GX, GXL and Cruiser RAV petrol models feature a 2.0-litre petrol engine driving the front wheels through a CVT transmission, with base GX also offering a six-speed manual gearbox. Equivalent hybrid models feature a more powerful 2.5-litre petrol-electric motor combination with CVT transmission and either 2WD or AWD ($3,000 extra). The only AWD non-hybrid variant is the most expensive Edge model. This features a 2.5-litre petrol engine eight-speed auto combination, but the hybrid still outguns it. New RAV4 has a very angular body shape which is pleasing enough. On the inside is a modern dash layout, good visibility, plenty of head and shoulder room and comfy front seats. Rear 60/40 seats deliver good comfort and a reclining function. The large cargo bay features a flat floor, cargo blind and optional full-size spare wheel. All models score a decent, vertically mounted stand-alone colour touchscreen with reverse camera, satellite navigation, DAB+ radio, Bluetooth connectivity and Toyota Link apps. There’s also dual

zone climate control with rear vents in all but base GX manual.

DRIVING

On the road, base GX Hybrid 2WD is impressive and can even be exhilarating. Where the standard RAV 2.0-litre petrol engine produces 127kW of power, the combined hybrid drivetrain punches out between 160kW (2WD) and 163kW (AWD). The power difference is immediately noticeable. Driven sedately, the hybrid combination is smooth, quiet and refined. Pushed hard it becomes a little noisy and more aggressive, delivering good acceleration even on the steepest hills. The steering is light and precise, and from the suspension comes good ride characteristics and excellent body control in corners and on rough dirt roads.