Morbidity and disability in 75- and 80-year-old men and women. A five-year follow-up

Purpose of this report is to describe the changes that occurred in morbidity, symptoms of illness and disability of 75- and 80-year-old residents of Jyväskylä, Finland, over a five-year period. The study population consisted of the elderly residents of the city of Jyväskylä in central Finland who were born in 1914 and 1910. At baseline (in 1989 and 1990), 355 (92.9%) persons from the younger age group and 262 (91.9%) from the older age group were interviewed and 311 (81.4%) and 230 (80.7%), respectively, took part in the physical examination. At follow-up (in 1994 and 1995), the corresponding numbers were 250 (93.3%) and 148 (88.6%) for the interviews and 217 (81.0%) and 127 (76.0%) for the physical examinations. The prevalence of chronic conditions was determined in connection with the medical examinations on the basis of self-report and the respondent's prescriptions and medical information cards. To measure the occurrence of symptoms, the respondents were asked whether during the past 14 days they had suffered from any of 17 listed symptoms. Functional capacity was assessed in connection with the interview carried out at the respondent's home in terms of needing help in activities of daily living (ADL). In the baseline examinations, subjects were found to have on average 2-3 diseases. During the follow-up the number of diseases and the proportion of people with co-morbidity increased in both age groups. Both men and women had on average 1-2 symptoms that caused them much trouble, and the number of such symptoms increased to some extent during the follow-up. The proportions of those needing help increased during the follow-up in all groups and the increase was most prominent among the women of the older age group. Of those who managed independently with physical ADL (PADL) at baseline, 14.9%-44.9% reported need of help in at least one task at follow-up. The need for help in PADL was greatest with cutting toe-nails, negotiating stairs, moving outdoors, washing the upper body and in instrumental ADL (IADL) with vacuuming, shopping, handling finances and in the use of public transport. Successful prevention and postponement of functional disabilities in the elderly population depends not only on the early diagnosis of illness but also on identifying even minor signs and symptoms of disease and functional limitations, and to focus health care interventions accordingly.

Maximal isometric knee extension strength and stair-mounting ability in 75- and 80-year-old men and women

The objective was to study whether the ability to mount different step heights depends on knee extension strength, and if this dependence varies according to age or sex among elderly persons. Altogether, 198 independently living 75-year-old women, 98 75-year-old men, 117 80-year-old women and 45 80-year-old men participated in the study. Maximal isometric knee extension strength was measured in a sitting position using a custom-built dynamometer chair. Results were standardized for body mass and height. In the stair-mounting test 10 cm high boxes were combined to form steps with heights of 10 to 50 cm. Older subjects, especially the women, exhibited poorer results in both tests. However, when groups based on maximum step height were analysed separately for strength, three-way analysis of variance revealed no sex effects. Although the number of men in the analysis was quite small, it was concluded that the strength requirements for mounting a certain step height were similar for both sexes. Owing to their sex-related lower average strength, old women may be at greater risk than old men of becoming impaired in certain motor tasks.

Postural balance and its sensory-motor correlates in 75-year-old men and women: a cross-national comparative study

BACKGROUND

There are no earlier cross-national comparative studies analyzing the functions of the posture control mechanisms and its sensory-motor correlates in elderly subjects. We investigated whether there are differences in balance between elderly subjects living in different geographical areas, and analyzed the sensory-motor associates of balance in men and women separately.

METHOD

Using a force platform method, the functioning of the posture control system under three standardized conditions (normal standing, eyes open; normal standing, eyes closed; and tandem standing, eyes open) was studied among samples of 75-year-old residents in three Nordic localities, namely Glostrup in Denmark, Göteborg in Sweden, and Jyväskylä in Finland. The associations of the variables describing performance in each test with other sensory and motor functions were studied using correlation analyses and multivariate regression models.

RESULTS

Differences between the populations were observed in both tests with visual control, favoring the participants from Glostrup and Jyväskylä compared with those from Göteborg. However, only minor differences between the subjects from different localities were observed in the test performed with the eyes closed. In all localities there was a primary sex difference in favor of the women which, however, mainly disappeared when body height was taken into the analyses as a covariate. A good performance in the balance tests (body height-adjusted values) was associated with good visual acuity, low vibrotactile thresholds, and high psychomotor speed. Also, isometric muscle strength, especially hand grip and body extension, was positively associated with good performance in the balance tests. Among the women, a poorer balance was observed in women with a smaller body mass. The results of the multivariate analyses showed that among the men, the most important predictors of good performance in the balance tests were low vibrotactile threshold on the foot, high isometric hand grip strength, and low body stature. Among the women, the most important predictors were low body stature, high body mass, high isometric body extension strength, and high psychomotor speed. However, only a small proportion of the variance in balance (about 13% in the men and 11% in the women) could be explained by the help of these factors.

CONCLUSIONS

As the same procedure was applied to the analysis of postural balance, some differences between the populations living in different localities could be detected in some of the tests. The better performance of the women in the balance tests may partly be explained by anthropometric factors, especially differences in body height. There may also be differences in sensory-motor associates of balance in elderly men and women. On the basis of the associations observed, it is difficult to explain the differences in balance between the sexes or subjects living in different localities. Within the sexes, only a small proportion (10-13%) of the variation in balance during normal standing with eyes open could be explained by the factors included in the study.

Serum and urine markers of type I collagen metabolism in elderly women with high and low bone mineral density

The serum markers of bone formation (carboxy-terminal propeptide of type I collagen, PICP) and resorption (pyridinoline cross-links containing telopeptide of type I collagen, ICTP), as well as urinary resorption markers, pyridinoline (Pyr) and deoxypyridinoline (Dpyr), were studied in 78-year-old women with high (n = 18) and low (n = 17) bone mineral density (BMD) measured from the calcaneus and tibia. The low-BMD group had higher values for PICP (P = 0 center dot 025), Pyr (P = 0 center dot 001) and Dpyr (P < 0 center dot 001) than the high-BMD group. No inverse relationship between these markers and BMD was, however, observed within the study groups. ICTP, Pyr and Dpyr correlated with each other in both groups and with PICP in the high-BMD group. Higher levels of both the formation and resorption markers of type I collagen suggest an increased rate of bone turnover and remodelling in osteopenic elderly women.

Difficulties in mobility among elderly people and their association with socioeconomic factors, dwelling environment and use of services

The purpose of this study was to clarify the extent to which elderly people have difficulties in mobility, and determine their association with socioeconomic factors, dwelling environment and use of services. The study groups were composed of two random samples of 800 persons aged 65-74 and 75-84, respectively. In all, 1224 non-institutionalized persons (80%) were interviewed at home. The respondents were asked to assess their ability to get about the house, negotiate stairs and walk outdoors, as well as manage certain physical exercise tasks. Difficulties in getting about outdoors were found most frequently among the women in the older age group (52% reported difficulties), and least frequently among the women in the younger age group (23%). Logistic regression analyses showed that difficulties in getting about outdoors were significantly explained by length of education and defects in the dwelling environment. Also, difficulties in getting about outdoors explained significantly the use of home help. It is concluded that difficulties in mobility among elderly people, especially among elderly women, should be reduced more actively either by improving their physical abilities or by developing compensation strategies for their own use or in regard to the environment.

Muscle strength and mobility as predictors of survival in 75-84-year-old people

The purpose of the study was to examine the association of physical capacity, as determined on the basis of self-report and physical measurements, with survival in three groups of elderly people aged 75, 80 and 75-84 years. The main aspects of physical capacity were mobility, walking speed, hand grip strength and knee extension strength. Although 1142 persons participated in mobility interview, of whom 466 also took part in the walking speed test, and 463 in the strength tests. The follow-up periods ranged from 48 to 58 months. Risk of death was significantly related to difficulties in indoor mobility among the 75-84-year-olds (odds ratio = 1.99, 95% confidence interval = 1.27-3.13) and 75- and 80- year-olds (OR = 1.60, CI = 1.07-2.38) and outdoor mobility among the 75-84-year-olds (OR = 2.44, CI = 1.63-3.67) and 75- and 80-year-olds (OR =2.75, CI = 1.72-4.40). The odds ratios for hand grip strength (OR = 1.86, CI=1.13-3.07), knee extension strength (OR =2.52, CI = 1.50-4.42) and walking time over 10 meters (OR = 1.98, CI = 1.18-3.34) for the 75- and 80-year-olds were also significant. Since these variables can be easily measured and provide valuable information about functional capacity and risk of death they merit inclusion in medical examination of elderly clients.

The pvB370 BamHI satellite DNA family of the Drosophila virilis group and its evolutionary relation to mobile dispersed genetic pDv elements

The pvB370 BamHI tandemly repeated satellite DNA family was isolated and analyzed in eight species of the Drosophila virilis group and is probably common to all its members. Unexpectedly, the satellite DNA family showed similar levels of intra- and interspecific sequence variability. An EMBL gene-bank search revealed a high degree of similarity between the members of the pvB370 BamHI satellite DNA sequence family and the direct terminal repeats of the mobile dispersed genetic pDv elements described in D. virilis and other species of the group. However, no similarity was observed to the transcribed and translated part of the pDv elements. It is suggested that the satellite DNA repeats are phylogenetically older than the mobile dispersed genetic pDv element and that the functional pDv elements might have derived from the satellite DNA family through an insertion of a tandemly repeated 36-bp transcription unit.

Factors related to carrying out everyday activities among elderly people aged 80

The study was based on an epidemiological model in which performing activities of daily living (ADL) was the dependent variable. Variation in performing was explained by physical and mental health, and by physical performance. The population consisted of all 80-year-old residents (N = 291) of the city of Jyväskylä in central Finland; 90% of them agreed to take part in the interviews at home, while 72% took part in the laboratory examinations to determine health status and functional capacity. Difficulties in at least some PADL (Physical Activities of Daily Living) tasks were reported by 86.5% of the men, and 87.2% of the women; none said they could perform all IADL (Instrumental Activities of Daily Living) tasks without difficulty. Physical performance (grip strength and stair mounting test in men, and stair mounting test, balance, and upper extremity function test in women) and visual acuity showed a significant association with ADL performance both in men and in women. In addition, depressive symptoms in women, and cognitive capacity in men were associated with both PADL and IADL, and ADL performance, respectively. In the search for pathways to reduced ADL performance, it is important to look not only at chronic diseases but also at the aging processes as well as the disabilities caused by inactivity. Tests of cognitive capacity, psychological well-being and physical performance provide valuable information on the factors that underlie the aged individual's reduced functional capacity.

Intraocular pressure in samples of elderly Finnish and Swedish men and women

Intraocular pressure was measured in 231 systematically sampled 75-year-old men and women in Göteborg, Sweden and in 284 75-year-old and 201 80-year-old residents in Jyväskylä, Finland as part of a comparative study on functional capacity and health, NORA 75 (Nordic Research on Ageing). After excluding the cases reporting glaucoma in their medical history or using drugs for glaucoma treatment there were no significant differences in the distributions of intraocular pressure between the men (mean intraocular pressure in the right eye 15.1 mmHg, left eye 15.0 mmHg) and women (mean intraocular pressure in the right eye 15.5 mmHg, left eye 15.8 mmHg) in Göteborg. In Jyväskylä the 75-year-old men had significantly lower intraocular pressure (right eye 13.4 mmHg, left eye 14.2 mmHg) than either the Jyväskylä women (right eye 15.1 mmHg, left eye 15.4 mmHg) or the men and women in Göteborg. Among the 80-year-olds in Jyväskylä there were no significant differences between the sexes (means for the right eye 14.0 mmHg and 13.7 mmHg and for the left eye 13.9 mmHg and 13.7 mmHg for the men and the women, respectively). The 80-year-old women had lower intraocular pressure than the 75-year-old women of either location. Ouclar hypertension (intraocular pressure 22 mmHg or higher) was more common among the Swedish 75-year-olds than among either the Finnish 75- or 80-year-olds.(ABSTRACT TRUNCATED AT 250 WORDS)

Maximal isometric strength and mobility among 75-year-old men and women

The purpose of this study was to examine the association between maximal isometric strength and mobility among 75-year-old men and women. All those born in 1914 and resident in the city of Jyväskylä in August 1989 comprised the study group (n = 388); 355 persons were interviewed at their homes (92%): 101 men (81% of all male residents) and 186 women (75%) participated in the laboratory strength tests. As part of the home interview the person's mobility at home, on stairs and outdoors was assessed using a four-point scale:--1 able, 2--able with difficulty, 3--needs help, 4--unable. Poor mobility was more common among the drop-outs than among the strength-tested subjects in both sexes. Maximal isometric strength of hand grip, arm flexion, knee extension and trunk flexion and extension were measured using specially constructed dynamometers. The strength results were adjusted for body weight. The study also included a stair-mounting test and measurement of maximal walking speed. The body-weight adjusted maximal forces were consistently significantly associated with mobility. Those who claimed no problems in the mobility interview and performed better in the walking and stair-mounting tests exhibited greater maximal isometric strength. The present results indicate that maximal isometric strength tests provide useful information about physical functional capacity among elderly people. These findings also suggest that the maintenance of adequate strength could be favourable to the mobility of older persons.

Bone density of the calcaneus and fractures in 75- and 80-year-old men and women

Bone mineral density of the calcaneus in relation to fractures was studied both retrospectively and prospectively among the 75- and 80-year-old men and women resident in the city of Jyväskylä, Finland, in 1989 and 1990, respectively. The bone measurements were performed at the calcaneus by 125I-photon absorption. Retrospective fracture (RF) history after age 50 was collected by questionnaire and interview, and reported fractures were checked from medical records. In the retrospective study, in the 75-year-olds a fracture was found in 22% (n = 22) of men and in 45% (n = 84) of women. The corresponding figures for the 80-year-olds were 16% (n = 9) and 35% (n = 48). Over half of the fractures were of the wrist/hand or ankle/leg. Prospective fractures (PF) were recorded over periods of 29-34 months. Twenty of the 75-year-olds and 16 of the 80-year-olds sustained a fracture during the follow-up period. In the 75-year-olds, the results showed that both RF and PF women, together with the RF men, had lower bone area density (BMDa) and volume density (BMDv) than the non-fracture (NF) subjects (p = 0.001-0.011). In the 80-year-olds, significantly lower BMDa was found in the RF women (p = 0.008) and lower BMDv in the PF women (p = 0.024) compared with the NF subjects. During the follow-up period there were no fractures in either of the sex or age groups among those with BMDa and BMDv values greater than 1 SD above the mean. (ABSTRACT TRUNCATED AT 250 WORDS)

NORA--Nordic research on ageing. Functional capacity of 75-year-old men and women in three Nordic localities

The aim of this cross-national study was to describe and compare differences in functional capacity of 75-year old people in three Nordic urban localities. As the life-expectancy at the age of 75 differs between the Nordic countries, there is reason to look for similar differences in functional capacity, taking differences in socio-demography, lifestyle, living conditions and health into consideration. In 1989-1991, 400 75-year-old men and women were selected to represent 75-year-olds in a Danish, Finnish and Swedish city. They participated in examinations which focused on functional capacity and health, where identical questionnaires, tests, and equipment were employed. The methods employed were developed from the experience gathered during previous studies of epidemiology of ageing in Glostrup, Gothenburg, and Jyväskylä. Functional capacity is the dependent variable multifactorially related to age, health, living conditions, and life style. The data collection was performed with participation rates in the interviews of 85% in Glostrup, 83% in Gothenburg, and 92% in Jyväskylä. The participation rates in the laboratory examinations were 76%, 67% and 77%, respectively. Examples of differences in socio-demographic background, lifestyle and measures of health and performance in the three localities are given. The Nordic study on physical, psychological and social capacity of 75-year-olds was performed with sufficiently standardised methods to allow a comparison of the results. Similar comprehensive cross-sectional comparative studies of the elderly people have not been performed earlier. Local and cross-national results will be published in each field separately and in combination.

Bone mineral density in relation to anthropometric properties, physical activity and smoking in 75-year-old men and women

Bone mineral content (BMC, g.cm-2) and density (BMD, g.cm-3) were studied in 75-year-old men and women in relation to anthropometric and certain life-style factors. This study covered all the men and women born in 1914 who were residents in the city of Jyväskylä in 1989 (N = 388). A hundred and three men and 188 women participated in bone measurements performed at the calcaneus using a 125I-photon absorption method. BMC was on average 36% and BMD 17% higher in the men than in the women. BMC and BMD associated with body mass in both sexes, and with body fat and use of estrogen in the women. There was a negative correlation between the BMD values and the number of cigarettes smoked over the entire life course in both sexes. Moderate physical activity was related to higher BMC in men. Men and women who had been physically active earlier in their life tended to show higher BMD values than those who had been more sedentary.

The changing panorama of shunt complications. Twenty-five years' experience

The distribution of shunt complications is analyzed in a series of 226 children and infants out of a total of 978 shunt operations performed between the years 1965 and 1989. The rate of shunt infections and obstructions has decreased significantly during the last ten years while the rate of CSF overdrainage complications has increased. A policy of active, elective shunt revisions has led to a reduction in the total rate of shunt revisions required. As only minor changes in the shunts available and used have taken place during the period converted, it is concluded that the main reason for the changing panorama of shunt revisions lies in improved neuroimaging and a better knowledge of complying with shunt complications.

Use of drugs by non-institutionalized urban Finns born in 1904-1923 and the association of drug use with mood and self-rated health

The purpose of this study was to examine the use of drugs by elderly people and to investigate its associations with various other factors. Random sampling was used to select 800 interviewees born in 1904-13 and a further 800 born in 1914-23. The average number of prescribed drugs per person was 2.2. Women used a greater number of prescribed drugs than did men; and this difference increased with age. The use of vitamins and trace elements seemed to decline with increasing age. Among women a significant association between the use of prescribed drugs and depressive symptoms was found. Women in the older age group used prescribed drugs more often than women in the younger age group. One fifth of the subjects had a greater number of drugs in simultaneous use than is generally recommended. It seems that, especially among elderly women, depression often remains undiagnosed and treatments are chiefly provided for the associated symptoms.

Imipenem-cilastatin vs. tobramycin and metronidazole for appendicitis-related infections

The efficacy of imipenem-cilastatin was compared with that of tobramycin and metronidazole for the treatment of appendicitis-associated abdominal infections in children in an open, randomized trial. Two hundred eighteen patients between 2.5 and 16.8 years of age hospitalized for appendectomy because of suspected acute appendicitis were allocated to 5 treatment groups. The appendix was perforated in 54 (33.8%) of the 160 cases with appendicitis. All patients responded favorably to treatment. Infection in the wound occurred in 15 of 125 (12.0%) of those without preoperative antibiotic therapy and in 5 of 83 (6.0%) of those given imipenem preoperatively (P = 0.12; 95% confidence interval, -2.2 to 14.2%). C-reactive protein decreased significantly faster in those with perforated appendix treated with imipenem than in those treated with tobramycin and metronidazole (58.2 mg/liter vs. 89.4 mg/liter, P less than 0.05 on the third postoperative day). Imipenem-cilastatin was at least as effective and economically comparable as tobramycin and metronidazole for the treatment of appendicitis-associated infections in children.

Muscle strength according to level of physical exercise and educational background in middle-aged women in Finland

The aim of this study was to examine the role of socio-economic status and the practice of physical exercise in explaining variation in muscle strength in 50 to 60-year-old women. Consequently, four study groups combining education and physical activity were formed: (1) university education, physically active; (2) university education, sedentary; (3) vocational or lower level of education, physically active; (4) vocational or lower level of education, sedentary. Maximal isometric strength of hand grip, arm flexion, body flexion and extension as well as dynamic power of the abdominal muscles were measured in 112 women. The results of the maximal isometric strength measurements were standardised by body mass index. The means of the maximal isometric strength results and sit-up tests were compared between the groups using two-way analysis of variance. The physically active women performed better than the sedentary in both the isometric and dynamic tests. Greater muscle strength was also found among the more highly educated compared with the less educated. The less educated sedentary women showed the poorest performance in the strength tests.

Determinants of isometric muscle strength in men of different ages

Values of maximal isometric strength of five muscle groups and associated factors including occupational status, life style and health were studied in three groups of men aged from 31 to 35, 51 to 55, and 71 to 75 years. The results indicated significant differences between the age groups in isometric handgrip, elbow flexion, knee extension, trunk extension and trunk flexion strength. In the youngest group, the manual workers tended to have higher strength values in all muscle groups than the lower and higher status white collar workers, whereas among the middle-aged and oldest men the manual workers tended to have the poorest performance. Good self-rated health and the intensity of physical exercise during leisure were positively associated with muscle strength in the youngest and middle-aged groups whereas in the oldest group the most important variable was home gymnastics. The multivariate structural equation models of isometric strength differed somewhat among the age groups and in these models the above-mentioned variables accounted for from 33% to 43% of the variance in isometric strength within the age groups. The results illustrated the most important factors associated with isometric strength in samples of men of different ages and also provided suggestions as to how these determinants might influence comparisons between different age groups in respect of muscle strength.

Sterility of male and female hybrids of Drosophila virilis and Drosophila lummei

The sterility of interspecific hybrids between the sibling species Drosophila virilis and D. lummei was tested in reciprocal F1s and different second generation combinations of cytoplasm, sex chromosomes and autosomes. Males with motile sperm and females with at least one mature egg were scored as fertile. When D. virilis was the mother, about 5 per cent of the F1 male progeny was sterile, the reason being that the X of D. virilis was weakly incompatible with the heterozygous second, fourth and fifth chromosomes. The F1 males carrying the X chromosome of D. lummei were all fertile. The X chromosome of D. lummei, and in particular its species-specific double inversion In(1)a + b, nevertheless caused sterility in 70 per cent of males in the presence of homozygous autosomes of D. virilis. Sterility was rare among the females, although some weakly disadvantageous X versus autosome and autosome versus autosome interactions were detected. The male and female hybrid sterilities were based on different genetic systems. The results emphasize the central role of the X chromosome in hybrid male sterility.

Ultrasonic features of the Osgood-Schlatter lesion

Ultrasound was used to compare the knees of 10 boys and four girls with typical clinical Osgood-Schlatter lesions with 27 symptomless knees. The normal sonographic changes of the tibial tubercle with advancing age are described. In all children with Osgood-Schlatter lesions, the distal patellar tendon thickened and became more echogenic than normal tendons, and an anechoic zone of edema was seen anterior to the tibial tuberosity. Four knees disclosed a thin shell-like elevated fragment of the tibial tuberosity seen as an echogenic surface. In 12 knees, single or multiple fragments of the tibial tuberosity were easily shown. Ultrasound is proposed as a simple, fast, and reliable method for the diagnosis of the Osgood-Schlatter lesion.

Wrinkling of the eye in hybrids between Drosophila virilis and Drosophila lummei is caused by interaction of maternal and zygotic genes

Hybrids of Drosophila virilis females and Drosophila lummei males have visible developmental anomalies in external adult structures. Reciprocal hybrids are normal, and the anomalies are not found in other interspecific F1 hybrids of the virilis subgroup. Antibiotic treatments with ampicillin, streptomycin and tetracycline did not cure the syndrome. The genetic basis of the wrinkling of the compound eye was analysed in detail. Both male and female F1 progeny of D. virilis mothers were affected, indicating that wrinkling of eyes is maternally determined. F1 hybrid females produced healthy progeny. Backcross hybrid females (D. virilis x F1) with 16 different combinations of autosomes, either heterozygous or homozygous for D. virilis, were crossed with D. lummei males. It was found that homozygous D. virilis chromosomes 2 and 5 together were necessary to induce the maternal effect. The hybrid zygote responded to the maternal effect when the chromosomes 2, 4 and/or 5 were heterozygous. Elimination of the small sixth (dot) chromosome of D. lummei from the hybrids was correlated with the wrinkling of eyes, but was not the cause, as the two phenomena had a different genetic basis and temperature response. Furthermore, the eyes were wrinkled in flies which presumably had had no D. lummei dot chromosome to lose.

Bone mineral density and physical activity in 50-60-year-old women

The bone mineral density (BMD) of the calcaneus was measured utilizing a single energy photon absorption method in 108 women, aged 50-60 years. The women who participated in vigorous exercise two or more times a week or whose total physical activity amounted to 4 h a week had significantly higher BMD values than those who exercised less than two times a week or did less than 4 h physical activity a week. The physically active women also showed higher values for leg extension force and maximal oxygen uptake. BMD and leg extension force were positively correlated, whereas correlations between BMD and body mass, and the width of the calcaneus were negative. When other life-style variables were taken into account, such as smoking and drinking, a significant difference in BMD was found between physically active and sedentary women, but not between the smokers and non-smokers, or the drinkers and non-drinkers.

Viability of first and second generation hybrids of Drosophila virilis and Drosophila lummei

F1 hybrids of D. virilis and D. lummei survived significantly worse than the parents. When D. virilis was the mother, larger proportion of hybrids failed to emerge from pupal case, but overall survival rate of reciprocals was about the same. Viability of different heterospecific combinations of sex chromosomes and autosomes was studied in backcrosses. All the sex chromosomes survived well on the background of all-heterozygous autosomes. Hemizygous X was reciprocally subvital with homozygous alien autosomes. The reduced viability was male sex limited. The X-linked factor causing this effect was localized in the area of the large, phylogenetically ancient double inversion In(1)a+b. All four large autosomes were heterotic in backcross hybrids, more strongly in females. Five out of six possible first degree interactions between the autosomes were negative, indicating incompatibility between heterospecific autosomes. This effect was stronger in females. The genetic basis for hybrid subvitality is sex-specific.