45(6):757-763,2004 PUBLIC HEALTH Social Variations in Infant Growth Performance in Severodvinsk, Northwest Russia: Community-based Cohort Study Andrej M. Grjibovski 1,2 , Lars O. Bygren 1,3 , Agneta Yngve 1 , Michael Sjöström 1 1 Unit for Preventive Nutrition, Department of Biosciences at NOVUM, Karolinska Institute, Huddinge, Sweden; 2 Institute of Hygiene and Medical Ecology, Northern State Medical University, Arkhangelsk, Russian Federation; and 3 Social Medicine, Department of Community Medicine and Rehabilitation, Umea University, Umea, Sweden Aim. To examine infant growth characteristics and their socio-demographic determinants in Severodvinsk, northwest Russia. Methods. Length-for-age, weight-for-age, and weight-for-length Z-scores of 1,067 infants born in 1999-2000 in Severodvinsk were calculated on the basis of the data on the length and weight obtained from the medical files. Multi- ple linear regression was used to estimate independent effects of maternal age, education, occupation, marital status, weight, parity, sex of the baby, and breastfeeding duration on infant growth. Results. At the age of 12 months, 1.1% of the infants were stunted, 1.1% underweight, and 0.5% wasted in comparison with the Centers for Disease Control and Prevention 2000 reference population. The mean Z-scores for length-for-age, weight-for-age, and weight-for-length were 0.48±0.93, 0.38±1.04, and 0.65±1.03, respectively. Mean weight-for- length Z-scores considerably increased from birth to 12 months, while length-for-age Z-score remained largely un- changed. In regression analysis, length-for-age Z-scores were lower by 0.43 (p=0.028) and by 0.30 (p<0.001) in in- fants born to mothers with basic and unknown education, respectively. Positive trends between linear growth and ma- ternal age (p=0.027) and education (p=0.024) were observed. No social variations in weight-for-length Z-scores were found. Conclusion. Prevalence of stunting, underweight, and wasting were lower than previously reported from Russia, which may reflect good overall socio-economic conditions in the town. Social variations in linear growth indicate the existence of inequalities in infant health, which may further increase with age. Key words: growth; infant; Russia; socioeconomic factors Infancy is the period of postnatal life when growth rates and nutritional demands are the highest (1). Even small changes in nutritional or health status are reflected in the changes in infant growth pattern. Impaired growth in this period is associated with in- creased risk of morbidity and mortality (2). Delayed consequences of growth failure in infancy may in- clude lasting deficits in growth (3), poor cognitive de- velopment (4), cardiovascular diseases (5), and re- duced work capacity (6). On the other hand, exces- sive weight gain during infancy is associated with in- creased risks of obesity in childhood (7) and young adulthood (8). Anthropometric characteristics are the main cri- teria used to assess the adequacy of infant growth (2). The most often used parameters are length-for-age, weight-for-age, and weight-for-length. Low length- for-age (stunting) reflects a failure to reach linear growth potential as a result of long-term cumulative inadequacies of nutrition and general health. Low weight-for-length (wasting) is often associated with acute malnutrition and/or severe illness. Low weight- for-age reflects both indicators. In addition to evaluat- ing health and nutritional status, growth assessment of infants and children provides good indirect mea- surement of social well-being of a population. This is particularly relevant for transitional economies due to the problems with measuring the actual income or the consumption in these countries (9). Although children have similar growth potential in infancy and early childhood, there is a wide varia- tion in infant growth characteristics among and within countries (10). A substantial part of this variation can be attributed to socio-economic determinants (11). Moreover, social, demographic, and economic fac- tors are more important than genetic attributes in pro- ducing deviations from the international reference values of child growth (12). Thus, studying social vari- ations in early child growth is of increased public www.cmj.hr 757