Inaccuracies in food and physical activity diaries of obese subjects: complementary evidence from doubly labeled water and co-twin assessments.

OBJECTIVE: To study whether eating or physical-activity (PA) habits differ between obese and non-obese monozygotic (MZ) co-twins independent of genetic effects. METHODS: Rare MZ pairs discordant for obesity (n=14, body mass index difference 5.2+/-1.8 kg m(-2)) and weight-concordant control pairs (n=10, 1.0+/-0.7 kg m(-2)), identified through a population-based registry of 24-28-year-old twins (n=658 MZ pairs), completed 3-day food and PA diaries and eating behavior questionnaires. Each twin was asked to compare his/her own eating and PA patterns with the co-twin's behavior by structured questionnaires. Accuracy of energy intake was validated by doubly labeled water. RESULTS: Non-obese co-twins consistently reported that their obese twin siblings ate more food overall, consumed less healthy foods and exercised less than the non-obese co-twins do. However, no differences in energy intake (9.6+/-1.0 MJ per day vs 9.8+/-1.1 MJ per day, respectively) in the food diaries or in the mean PA level (1.74+/-0.02 vs 1.79+/-0.04, respectively) in the PA diaries were found between obese and non-obese co-twins. A considerable underreporting of energy intake (3.2+/-1.1 MJ per day, P=0.036) and overreporting of PA (1.8+/-0.8 MJ per day, P=0.049) was observed in the obese, but not in the non-obese co-twins. CONCLUSIONS: On the basis of rare MZ twin pairs discordant for obesity, the co-twin assessments confirmed substantial differences in eating and PA behavior between obese and non-obese persons. These may be overlooked in population studies using food and PA diaries because of considerable misreporting by the obese.

Pneumococcal carriage and otitis media induce salivary antibodies to pneumococcal surface adhesin a, pneumolysin, and pneumococcal surface protein a in children.

Local antibodies probably contribute to defense against Streptococcus pneumoniae. This study examined whether pneumococcal carriage and acute otitis media (AOM) induce mucosal antibodies to potential vaccine candidates pneumococcal surface adhesin A (PsaA), pneumolysin (Ply), and pneumococcal surface protein A (PspA). IgA to all 3 proteins was detected by EIA in saliva of 329 children at ages 6, 12, 18, and 24 months and of 17 adults. A higher proportion of IgA-positive samples and higher antibody concentrations were seen in children with pneumococci-positive cultures of nasopharyngeal samples or middle ear fluid than in children with all cultures negative for pneumococci. The strong correlation between IgA and the presence of the secretory component suggests that the IgA was secretory. The findings indicate that pneumococcal carriage and AOM induce local production of anti-PsaA, anti-Ply, and anti-PspA antibodies early in life.

Serum and salivary anti-capsular antibodies in infants and children immunized with the heptavalent pneumococcal conjugate vaccine.

AIM: To study the ability of seven-valent experimental pneumococcal polysaccharide CRM197 protein conjugate vaccine (PncCRM) to induce antibodies in serum and saliva of infants. METHODS: Sixty Finnish infants received Pnc-CRM vaccine at 2, 4 and 6 months of age and were boosted with PncCRM (n = 30) or pneumococcal polysaccharide (PncPS) (n = 29) vaccine at the age of 15 months. Serum IgG antibody concentrations to vaccine serotypes 4, 6B, 9V, 14, 18C, 19F and 23F were measured by enzyme immunoassay at 2, 4, 6, 7, 15, 16 and 24 months of age. Salivary IgA, IgG and secretory Ig antibody titers at 7 and 16 months of ages were analyzed by enzyme immunoassay against the same serotypes, except 23F. RESULTS: PncCRM induced systemic immune responses and immunologic memory. At 7 months of age 69 to 100% of children, depending on the serotype, had serum IgG antibody concentrations exceeding the value of 1.0 microg/ml. At 15 months the titers were still higher than before the vaccinations. Booster doses of either PncPS or PncCRM induced an increase in antibody concentrations. The titers were still elevated at 24 months of age. Salivary IgA and IgG antibodies were found rarely at 7 months of age, but in up to 80% of samples taken at 16 months of age, depending on the serotype and nature of the booster vaccine. Salivary IgG correlated with IgG in serum, supporting the theory that salivary IgG is derived from serum. Salivary IgA and secretory Ig correlated positively, which indicates that IgA was locally produced. CONCLUSIONS: PncCRM induces both systemic and mucosal immune responses in infants.

Salivary anti-capsular antibodies in infants and children immunised with Streptococcus pneumoniae capsular polysaccharides conjugated to diphtheria or tetanus toxoid.

Saliva samples of infants and children immunised with pneumococcal vaccines were analysed for anti-polysaccharide (PS) antibodies against the Streptococcus pneumoniae (Pnc) vaccine serotypes 6B, 14, 19F, and 23F. The children received Pnc conjugate vaccine (1, 3, or 10 micrograms of PSs conjugated to diphtheria or tetanus toxoid) or placebo at 2, 4, and 6 months. At 7 months of age salivary PS antibodies were detected rarely. All children received Pnc conjugate or PS vaccine at 14 months of age. At 15 months, both IgA and IgG anti-Pnc PS were found, anti-19F and anti-14 antibodies occurring most frequently and in the highest concentrations. IgA was in the secretory form and predominantly IgA1. A negative dose dependency was observed in IgA anti-19F response. In general, no clear differences in salivary antibody responses were found between the children primed with conjugate vaccine in infancy and those who received their first Pnc vaccine at 14 months of age, suggesting that priming with Pnc conjugate vaccines does not lead to remarkable mucosal memory responses.

Costs of care, long-term prognosis and quality of life in patients requiring renal replacement therapy during intensive care.

OBJECTIVE: To assess (1) the long-term outcome of patients requiring renal replacement therapy (RRT) in terms of 6-month and 5-year mortality, (2) quality of life and (3) costs of the intensive care. DESIGN: A retrospective observational cohort study. SETTING: Twenty-three-bed multidisciplinary intensive care unit (ICU) in a tertiary care center. PATIENTS AND PARTICIPANTS: Out of 3,447 intensive care patients admitted, 62 patients with no end-stage renal failure required RRT. INTERVENTIONS: None. MEASUREMENTS AND RESULTS: The incidence rate of acute renal failure (ARF) was 8/100,000 inhabitants/ year. The majority of patients (71%) had ARF in conjunction with multiple organ failure. The mortality in the ICU and in the hospital was 34 % and 45%, respectively. Mortality was 55% at 6 months and 65 % at 5 years. Renal function recovered in 82 % of the survivors during hospitalization. Loss of energy and limitations of physical mobility assessed by Nottingham Health Profile were the most frequently reported complaints at 6 months. Functional ability, as assessed by the Activities of Daily Living score was fairly good at 6 months. The cost per ARF 6-month survivor was $80,000. CONCLUSIONS: There was only a minor increase in mortality after discharge from hospital among patients treated for ARF in intensive care. The costs related to ARF in intensive care are high, but the almost complete physical and functional recovery seen in ARF survivors should be noted in cost-effective analyses.

Weight-loss attempts and risk of major weight gain: a prospective study in Finnish adults.

BACKGROUND: The effects of weight-loss attempts on long-term weight gain remain unclear. OBJECTIVE: The objective was to study prospectively how attempts to lose weight relate to future risk of major weight gain (>10 kg) and whether familial factors affect this relation. DESIGN: Participants in the Finnish Twin Cohort (3536 men and 4193 women aged 18-54 y at baseline) were followed up for 6-15 y. The role of familial factors was studied in 1705 twin pairs in this cohort who were discordant for weight-loss attempts at baseline. Baseline (1975) and follow-up (1981 and 1990) data-including weight, weight-loss attempts (dieting), and selected confounders-were obtained via mailed questionnaires. RESULTS: Average weight gain was at most weakly associated with weight-loss attempts. The risk of major weight gain for subjects attempting to lose weight at baseline was greatest among initially young (18-29 y) men (over 6 and 15 y, respectively-odds ratios: 2.01 and 1.74; 95% CI: 1.13, 3.57 and 1.11, 2.75) and middle-aged (30-54 y) women (over 6 and 15 y, respectively-2.43 and 1.52; 1.33, 4.42 and 1.06, 2.22) and persisted after potential confounders were controlled for. These risks decreased and became nonsignificant in the pairwise twin analysis, suggesting that the relation between dieting and subsequent major weight gain may also have a familial component. CONCLUSIONS: Weight-loss attempts may be associated with subsequent major weight gain, even when several potential confounders are controlled for. Genetic and familial factors may contribute to this association.

Predictors of major weight gain in adult Finns: stress, life satisfaction and personality traits.

OBJECTIVE: To study how stress, life satisfaction and personality related factors, are related to long-term major weight gain. DESIGN: Prospective cohort study, with follow-up by questionnaire at 6 y and 15 y with a within-study replication. SUBJECTS: 5867 twin pairs aged 18-54 y at baseline, considered as two sets of unrelated individuals in analyses. MAIN OUTCOME MEASURES: Adjusted odds ratios (OR) for 10 kg weight gain over 6 y and 15 y. RESULTS: A high level of stress at baseline, was a predictor for major weight gain over 6 y, and this effect was consistent in some groups even over 15 y. Low levels of life satisfaction and high scores for neuroticism, were predictors for weight gain in older women. These effects were consistent, even after adjustments for confounding variables (education, dieting, smoking, alcohol consumption and pregnancy in women). High levels of extroversion showed a trend towards lesser weight gain in younger men. CONCLUSION: Psychological traits did not affect the risk of major long-term weight gain in a uniform fashion. The observed effects of the factors related to psychological health were modest and consistent, but varied by age and gender. Thus, there may be trait-specific effects in selected subgroups of the population that should be further investigated.

Subclass distribution of IgA antibodies in saliva and serum after immunization with Haemophilus influenzae type b conjugate vaccines.

IgA subclass distribution of antibodies against capsular polysaccharide (PS) of Haemophilus influenzae type b (Hib) was studied in saliva and serum samples of children vaccinated with two (n = 58) or three doses (n = 53) of Hib vaccine. One month after the second dose of Hib conjugate vaccine, at 7 months old, 40% of the children had IgA1 and 41% had IgA2 anti-Hib PS antibodies in saliva. One month after the third dose, at 15-25 months old, IgA1 was the predominating subclass; 72% of the children had IgA1, 26% had IgA2 anti-Hib PS in saliva. The mean concentration of IgA1 anti-Hib PS, expressed as optical density (OD) values, was significantly higher after three doses (OD 80.7) than after two doses (OD 18.9). The mean concentration of IgA2 did not change significantly after the third dose (OD 23.8 after two doses, OD 18.1 after three doses). In serum, IgA1 anti-Hib PS predominated both after two (17% had IgA1, none had IgA2) and three doses (72% had IgA1, 4% had IgA2) of Hib vaccine. In conclusion, both IgA1 and IgA2 anti-Hib PS were found in saliva of immunized children after two doses of Hib conjugate vaccine, whereas the third vaccine dose induced a shift towards IgA1 anti-Hib PS dominance in saliva.

Are genetic determinants of weight gain modified by leisure-time physical activity? A prospective study of Finnish twins.

A large number of studies have shown that obesity is both under genetic control and influenced by several environmental factors, including energy expenditure and intake. Several studies in animals and humans have furthermore suggested that certain environmental factors, such as a high fat intake, may modify the expression of the genes responsible for weight gain. The present study examined whether physical activity, measured at the baseline examination in 1975, was likely to play a differential role in subsequent weight changes in the following 6 y in 1571 monozygotic and 3029 dizygotic, same-sex twin pairs from the Finnish Twin Cohort Study. A hierarchical multiple-regression analysis was used to test for gene-environment interactions by identifying significant three-way interactions between genetic factors, physical activity, and weight change. The results showed that associations between weight change in twin A and twin B were significantly stronger for monozygotic than for same-sex dizygotic twins at all levels of physical activity. Additionally, in the monozygotic men the strength of the association varied with physical activity level, and the association between the change in body mass index between the twin pairs with the highest physical activity level was about three times stronger (beta = 0.40) than the association in twin pairs with the lowest physical activity level (beta = 0.15, P for trend = 0.002). In pairs of dizygotic men, and in both monozygotic and dizygotic women, similarity in body mass index change was independent of physical activity level (all P > 0.14). The present study showed that genetic factors may modify the effects of physical activity on weight change, and suggests that a sedentary lifestyle may have an obesity-promoting effect in men with a genetic predisposition.

Mechanism of antibody-mediated reduction of nasopharyngeal colonization by Haemophilus influenzae type b studied in an infant rat model.

The mechanism of antibody-mediated reduction of Haemophilus influenzae type b (Hib) carriage was studied in the infant rat colonization model. Monoclonal Hib polysaccharide (PS) antibody (MAb) given intranasally or intraperitoneally and human secretory anti-Hib PS IgA given intranasally inhibited colonization by Hib during the entire follow-up period (2-48 h after challenge) but did not affect colonization by Hi, a noncapsulated variant of Hib. F(ab')2 fragments, prepared from the MAb or from human serum anti-Hib IgG reduced Hib colonization as efficiently as the uncleaved molecules. Complement depletion by cobra venom treatment had no effect on the antibody-mediated reduction of Hib colonization. These results indicate that Fc-mediated activities of immunoglobulins are not essential in the reduction of Hib colonization. Instead, antibodies to Hib most likely reduce colonization by a direct effect on growth of the bacteria or their adherence to the nasopharyngeal mucosa.

The heritability of body mass index among an international sample of monozygotic twins reared apart.

BACKGROUND: Published heritability estimates (h2) for body mass index (BMI) range from as low as 0.05 to as high as 0.90. The purpose of this paper is to introduce new data to help narrow the range of plausible estimates. SUBJECTS: Subjects were 53 pairs (23 M; 30 F) of monozygotic twins reared apart (MZAs), whose mean BMI was 24.2 (SD = 4.7). BMI's were transformed to approximate normality via the Box-Cox transformation. Twin paris came from the Finnish Twin Cohort (17 pairs), a data base of Japanese twins (10 pairs) and published case histories of primarily American twins (26 pairs). RESULTS: The h2 for MZAs is given by the correlation among the twin pairs. For the transformed data, the zero-order correlation of twins' BMIs was 0.79 for all twins, 0.63 for the Finnish twins, 0.73 for the Japanese twins and 0.85 for the 'archival' twins. When modeled with regression to control for relevant covariates, the estimate of h2 is either 0.50 or 0.70, depending on one's definition. The semipartial r was 0.50, suggesting that 50% of the total variance in BMI appears to the genetic in origin after controlling the covariates. The partial r was 0.70, suggesting that 70% of the variance in BMI that is not accounted for by the covariates can be attributed to genetic variation. Separation age had a small positive correlation with absolute intra-pair difference in BMI, suggesting that these estimates of h2 are not biased upwards due to early shared environment. CONCLUSIONS: Findings are consistent with past studies of MZAs and suggest that h2 estimates between 0.50 and 0.70 are reasonable. Implications of this finding are discussed.

Consistency and change of body mass index and weight. A study on 5967 adult Finnish twin pairs.

OBJECTIVE: To study twin resemblance for weight change (delta wt) and to assess the consistency of body mass index (BMI) over 6 years. DESIGN: 6 year follow-up based on identical mailed questionnaires in 1975 (baseline) and in 1981 (follow-up). SUBJECTS: 5967 same-sexed non-pregnant Finnish twin pairs aged 18-54 in 1975 (1106 male and 862 female monozygotic (MZ) and 2430 male and 1569 female dizygotic (DZ) pairs). MAIN OUTCOME MEASURES: Intra-pair correlations of delta wt and BMI, estimates of genetic and environmental components of variance of delta wt and BMI. RESULTS: Unadjusted mean delta wt was +2.0 (s.d. = 4.6) kg among MZ and 2.1 (4.9) kg among DZ male individuals. Corresponding values among MZ and DZ female individuals were +1.5 (4.4) kg and +1.7 (4.4) kg, respectively. Age and initial BMI together explained 8.0% of the male and 2.3% of the female phenotypic variance of delta wt. The intraclass correlations for delta wt (adjusted for age and initial BMI) for all pairs were 0.29 and 0.07 for MZ and DZ men and 0.25 and 0.05 for MZ and DZ women, respectively. The BMI of the twins increased slightly during the follow-up compared to the baseline values (23.9 (2.7) for MZ and 24.1 for DZ men and 23.0 (3.3) for MZ and 23.2 (3.42) for DZ women). The intra-class correlations for BMI at baseline (0.69 for MZ and 0.34 for DZ men and 0.67 for MZ and 0.29 for DZ women) were almost identical with the correlations at follow-up (0.67 for MZ and 0.32 for DZ men and 0.69 for MZ and 0.29 for DZ women). The intra-class correlations for both BMI and delta wt were consistently higher among pairs living together than among pairs living apart at baseline and at follow-up in both zygosity groups (MZ and DZ). Among pairs living apart at baseline, the longitudinal model for BMI showed that the correlation between genetic effects at baseline and at follow-up was very high (> 0.9 in all age groups among both genders). The correlations for environmental effects ranged from 0.50 to 0.67 during the follow-up period. CONCLUSION: Weight changes in adults over a 6-year period appear to be determined by environmental effects rather than genetic factors. However, the genetic component in BMI is considerable and stable over time. Shared environment is likely to contribute to the resemblance of both delta wt and BMI among adult twin pairs, especially among MZ pairs.

Effects of gender and age on the heritability of body mass index.

We estimated genetic and environmental components of variance of body mass index (BMI) among 7245 same-sexed Finnish MZ and DZ twin pairs aged 18-54 years from the nationwide Finnish Twin Cohort. Age accounted for 20 per cent of variance among men and 26 per cent in women. The contributions of additive genetic effects, shared and non-shared environmental effects on BMI-variance were estimated by LISREL structural equation models. Genetic effects accounted for 72 per cent and 68 per cent of total variance in men and non-pregnant women respectively, while 28 per cent of variance among men and 32 per cent among women was due to non-shared environmental effects. This gender difference was statistically significant. Models including shared environmental effects did not improve model fits. The magnitude of the genetic component of BMI was also analysed separately for each 10-year age group. Models with age-specific parameters for genetic and environmental effects fitted significantly better than models with effects constrained to be equal over age. Our results indicate a substantial genetic component in BMI. However, the magnitude of additive genetic effects decreases with age in both genders.