Aims/hypothesis. The aim of the Diabetes Prevention Study is to assess the efficacy of an intensive diet-exercise programme in preventing or delaying Type II (non-insulin-dependent) diabetes mellitus in subjects with impaired glucose tolerance, to evaluate the effects of the intervention programme on cardiovascular risk factors and to assess the determinants for the progression to diabetes in persons with impaired glucose tolerance. Methods. A total of 523 overweight subjects with impaired glucose tolerance ascertained by two oral glucose tolerance tests were randomised to either a control or intervention group. The control subjects received general information at the start of the trial about the lifestyle changes necessary to prevent diabetes and about annual follow-up visits. The intervention subjects had seven sessions with a nutritionist during the first year and a visit every 3 months thereafter aimed at reducing weight, the intake of saturated fat and increasing the intake of dietary fibre. Intervention subjects were also guided individually to increase their physical activity. Results. During the first year, weight loss in the first 212 study subjects was 4.7 ± 5.5 vs 0.9 ± 4.1 kg in the intervention and control group, respectively (p < 0.001). The plasma glucose concentrations (fasting: 5.9 ± 0.7 vs 6.4 ± 0.8 mmol/l, p < 0.001; and 2-h 7.8 ± 1.8 vs 8.5 ± 2.3 mmol/l, p < 0.05) were significantly lower in the intervention group after the first year of intervention. Favourable changes were also found in blood pressure, serum lipids and anthropometric indices in the intervention group. Conclusion/interpretation. The interim results show the efficacy and feasibility of the lifestyle intervention programme. [Diabetologia (1999) 42: 793±801]

Objectives-To investigate the association between leisure physical activity and various pain symptoms in adolescents. Methods-In this nationwide cohort based cross sectional study in Finland, 698 schoolchildren, 344 girls and 354 boys, aged 10 to 17 years responded to a questionnaire on pain symptoms (neck and shoulder pain, upper back pain, low back pain, upper limb pain, lower limb pain, headache, and abdominal pain) and physical activity habits and also participated in a fitness test. Results-Reported physical activity correlated with measured fitness. Musculoskeletal pains (p = 0.013) (in particular low back pain (p = 0.022), upper limb pain (p<0.001), and lower limb pain (p<0.001)) were found more often in subjects participating in large amounts of leisure physical activity, while non-musculoskeletal pains (p = 0.065) (in particular headache among boys (p = 0.004)) tended to be less common. Co-occurrence of diVerent musculoskeletal pains was common in subjects participating in sports. Conclusions-In addition to its likely long term health benefits, vigorous physical activity causes musculoskeletal pains during adolescence. This should be considered when tailoring health promotion programmes to adolescents. Also, cooccurrence of musculoskeletal pains may occur as the result of sports activity, which should be considered as a confounder in epidemiological studies on fibromyalgia and related issues. (Br J Sports Med 1999;33:325-328)

Low back pain is a relatively common complaint at adolescence. In addition, a significant part of the pains are recurrent or chronic already with 14-year-old adolescents.

We review new data derived from careful dissection studies on the macroscopic anatomy, innervation and function of the lumbar muscles, as well as information on the fibres in these muscles. The new findings correct previous misconceptions of the functional anatomy of the lumbar muscles. The innervation and function of the erector spinae and multifidus muscles are so different that they cannot be classified as a single unit. The new interpretation of the innervation of multifidus muscle is of importance, for example, for the neurophysiological examination of the lumbar muscles. The relative number of the slow and fast type of muscle fibres in lumbar muscles varies considerably, and selective atrophy of the fast fibres seems to ensue from inactivity, not only in patients with back pain but also in sedentary controls. The atrophy may be corrected by adequate exercise. Both the fibre type composition and degree of atrophy may well influence a person's susceptibility to low back pain arising from the muscles.

We investigated muscle strength, aerobic power, and occupational and leisure-time physical loading as predictors of back pain in a 5-year follow-up study. A cohort of 456 adults aged 25, 35, 45 and 55 years, free of back pain, participated in measurements of anthropometric characteristics, aerobic power and muscle strength characteristics at baseline. The subjects' levels and types of physical activity and occupational physical loading were also determined. At 5 years after the baseline examinations 356 of these subjects (78.1%) were reached by mail, and 262 of them (73.6%) properly completed and returned a questionnaire including a detailed back pain history for the 5 years following the baseline measurements. Of this number 56 subjects (21%) who reported back pain (> 30 on a scale from 0 to 100) and functional impairment during the 5-year follow-up composed the marked back pain group. Other subjects (n = 71, 27%) noting lesser symptoms were included in the mild back pain group; 135 subjects (52%) reported having had no back pain. The subjects with marked back pain were on average taller than the subjects without back pain, while no such difference was found in body mass. Heavy occupational musculoskeletal loading (P = 0.005) and high general occupational physical demands (P = 0.036) predicted future back pain. Leisure-time physical activity, aerobic power or muscle strength characteristics were not predictive of future back pain.