Lower Birth Weight and Visceral Fat Accumulation Are Related to Hyperinsulinemia and Insulin Resistance in Obese Japanese Children

The effect of low birth weight as an intrauterine exposure on the early onset of sarcopenia through possible molecular pathways

Sarcopenia, a musculoskeletal disease characterized by the progressive loss of skeletal muscle mass, strength, and physical performance, presents significant challenges to global public health due to its adverse effects on mobility, morbidity, mortality, and healthcare costs. This comprehensive review explores the intricate connections between sarcopenia and low birth weight (LBW), emphasizing the developmental origins of health and disease (DOHaD) hypothesis, inflammatory processes (inflammaging), mitochondrial dysfunction, circadian rhythm disruptions, epigenetic mechanisms, and genetic variations revealed through genome-wide studies (GWAS). A systematic search strategy was developed using PubMed to identify relevant English-language publications on sarcopenia, LBW, DOHaD, inflammaging, mitochondrial dysfunction, circadian disruption, epigenetic mechanisms, and GWAS. The publications consist of 46.2% reviews, 21.2% cohort studies, 4.8% systematic reviews, 1.9% cross-sectional studies, 13.4% animal studies, 4.8% genome-wide studies, 5.8% epigenome-wide studies, and 1.9% book chapters. The review identified key factors contributing to sarcopenia development, including the DOHaD hypothesis, LBW impact on muscle mass, inflammaging, mitochondrial dysfunction, the influence of clock genes, the role of epigenetic mechanisms, and genetic variations revealed through GWAS. The DOHaD theory suggests that LBW induces epigenetic alterations during foetal development, impacting long-term health outcomes, including the early onset of sarcopenia. LBW correlates with reduced muscle mass, grip strength, and lean body mass in adulthood, increasing the risk of sarcopenia. Chronic inflammation (inflammaging) and mitochondrial dysfunction contribute to sarcopenia, with LBW linked to increased oxidative stress and dysfunction. Disrupted circadian rhythms, regulated by genes such as BMAL1 and CLOCK, are associated with both LBW and sarcopenia, impacting lipid metabolism, muscle mass, and the ageing process. Early-life exposures, including LBW, induce epigenetic modifications like DNA methylation (DNAm) and histone changes, playing a pivotal role in sarcopenia development. Genome-wide studies have identified candidate genes and variants associated with lean body mass, muscle weakness, and sarcopenia, providing insights into genetic factors contributing to the disorder. LBW emerges as a potential early predictor of sarcopenia development, reflecting the impact of intrauterine exposures on long-term health outcomes. Understanding the complex interplay between LBW with inflammaging, mitochondrial dysfunction, circadian disruption, and epigenetic factors is essential for elucidating the pathogenesis of sarcopenia and developing targeted interventions. Future research on GWAS and the underlying mechanisms of LBW-associated sarcopenia is warranted to inform preventive strategies and improve public health outcomes.

Physique at Birth and Cardiovascular Disease Risk Factors in Japanese Urban Residents: the KOBE Study

Aim: This study investigated the relationship between birth physique and cardiovascular risk factors in Japanese urban residents aged 40 years and more.

Methods: A self-administered questionnaire on birth physique was performed among 624 individuals (165 men and 459 women) who participated in the KOBE study. We examined whether self-reported birth physique and available recorded birth weights matched for 72 participants. Then the association between birth physique and risk factors for all participants was examined by gender. Body size at birth in the questionnaire (large, medium, small) was set as an exposure and laboratory values from the baseline survey (2010-2011) were used as outcomes.

Results: Mean (standard deviation) recorded birth weight of 72 participants was 3665 (318), 3051 (300), and 2653 (199) g, in the large, medium, and small group, respectively. In the analysis for all participants, odds ratio for having both hypertension and impaired glucose tolerance were significantly higher in the small versus large birth weight group, which was 7.42 (95% CI 1.75–31.50) for men and 4.44 (95% CI 1.14–17.30) for women after adjusting for age, body mass index, smoking/alcohol/exercise habits, and menstrual status in women. Similar results were observed in participants with recorded birth weight.

Conclusions: The present study indicates that individuals with small physique at birth might be at higher risk for hypertension and impaired glucose tolerance in middle age compared to those with large birth weight.

Low birth weight and abnormal pre-pregnancy body mass index were at higher risk for hypertensive disorders of pregnancy

Low birth weight is known to be associated with hypertension, cardiovascular disease and hypertensive disorders of pregnancy (HDP); however, this association might vary by race/ethnicity. This study aimed to clarify the association between women's own birth weight and their subsequent risk for HDP in a Japanese population, in combination with pre-pregnancy body mass index (BMI). We conducted a cohort study as part of the Tohoku Medical Megabank Birth and Three-Generation Cohort Study in Miyagi, Japan. Our study's population included 4810 women. A multivariate logistic regression analysis was performed to calculate the adjusted odds ratio (aOR) and the 95% confidence interval (CI) of the women's own birth weight for HDP, in the combination categories of birth weight and pre-pregnancy BMI. As a result, the group with a low birth weight of <2500 g had a significant association with HDP (the aOR, 1.50; 95% CI, 1.02-2.21). In the subtype analysis, the odds ratio for only preeclampsia was significantly increased in the low birth weight group (aOR, 3.37; 95% CI, 1.84-6.16). In the group with a low birth weight, the prevalence of HDP was higher in both the underweight and overweight groups. In conclusion, there was a significant association between low birth weight and subsequent HDP in Japanese women. Furthermore, a significant association with HDP was found for women born with a low birth weight who were underweight or overweight as adults. Maintaining a normal weight may be effective for preventing HDP even if a woman was born small.

Relationship between thin physique at 6 years and metabolic disease risks in middle-aged Japanese women: The Suita study

AIM

We previously reported that female babies born small developed cardiovascular risks in middle age. The present study was conducted using the same cohort to examine the relationship between physique at 6 years and the metabolic disease risk in middle age.

METHODS

Data collected from 721 women aged 41-69 years who underwent a medical examination at a single institution between 2007 and 2008 were retrospectively examined. We collected data from medical examinations and a questionnaire on physique (thin, normal, and fat) at 6 years. The relationship between birthweight and physique at 6 years was investigated.

RESULTS

Among females who were born small (< 2500 g), 80%, 16%, and 4% became thin, normal, or fat, respectively, by 6 years. Physique at 6 years had a negative relationship with future triglyceride, fasting glucose, HbA_1C , insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) levels and a positive relationship with high-density lipoprotein cholesterol levels.

CONCLUSION

Although our findings may be specific to the study population, physique at 6 years had a negative relationship with the metabolic disease risk in middle-aged Japanese women. Insulin and MOMA-IR levels negatively correlated with physique at 6 years, and development from low birthweight infants to childhood obesity was rare in this cohort.

Adrenal Function in Adolescence is Related to Intrauterine and Postnatal Growth

Background and objectives: Intrauterine growth restriction is thought to be implicated in long-term programming of hypothalamic-pituitary-adrenal axis activity. We investigated adrenal function in adolescents born small for gestational age (SGA) in relation to their postnatal growth and cardiovascular parameters. Materials and Methods: Anthropometric parameters, blood pressure, heart rate, dehydroepiandrosterone sulfate (DHEAS), and cortisol levels were assessed in 102 adolescents aged 11-14 years followed from birth (47 SGA and 55 born appropriate for gestational age (AGA)). Results: Mean DHEAS levels were higher in SGA adolescents with catch-up growth (SGACU+), compared with AGA. Second-year height velocity and body mass index (BMI) gain during preschool years were positively related to DHEAS levels. Morning cortisol levels and systolic and diastolic blood pressure were higher in SGA adolescents without catch-up growth (SGACU-) compared with AGA. Second-year BMI gain was inversely, and 2-12 years increase in subscapular skinfold thickness was directly associated with cortisol levels. Size at birth and postnatal growth explained 47.8% and 38.2% of variation in DHEAS and cortisol levels, respectively. Conclusion: Adrenal function in adolescence is affected by prenatal and postnatal growth: small size at birth with postnatal catch-up growth is related to higher DHEAS secretion, whereas increased cortisol levels and blood pressure are higher in short SGA adolescents.

Long-term metabolic risk among children born premature or small for gestational age

Accumulating evidence suggests that both the intrauterine environment and growth during early life can influence the development of chronic noncommunicable diseases, such as type 2 diabetes mellitus and cardiovascular disease, in adulthood. Here, we review the available human data supporting increased metabolic risk among children born premature or small for gestational age; the adrenal and pubertal modifications that contribute to this risk; metabolic changes that occur during adolescence and early adulthood; and approaches to potentially modify or decrease risk of metabolic disease. The risks associated with delivery at term or preterm are compared for each period of life. Knowledge of these associations is fundamental for the paediatric community to develop preventive strategies early during postnatal life.

The sequence of prenatal growth restraint and post-natal catch-up growth leads to a thicker intima-media and more pre-peritoneal and hepatic fat by age 3-6 years

BACKGROUND

Infants born small-for-gestational-age (SGA) who develop post-natal weight catch-up are at risk for insulin resistance, central adiposity and cardiovascular disease in later life, even in the absence of overweight.

OBJECTIVE

In young (age 3-6 years) non-obese SGA children, we assessed arterial health (as judged by intima-media thickness [IMT]) and abdominal fat distribution (subcutaneous, visceral, preperitoneal and hepatic components by magnetic resonance imaging [MRI] and/or ultrasound [US]) besides a selection of endocrine markers.

METHODS

Comparisons of measures in SGA (n = 27) vs. appropriate-for-GA (AGA) children (n = 19) of similar height, weight and body mass index. Longitudinal outcomes (age 3-6 years) were carotid IMT (cIMT); fasting glucose, circulating insulin, IGF-I and high-molecular-weight (HMW) adiponectin; abdominal fat partitioning by US. Cross-sectional outcomes (age 6 years) were aortic IMT (aIMT) and abdominal fat partitioning by MRI.

RESULTS

At 3 and 6 years, cIMT and IGF-I results were higher and HMW adiponectin lower in SGA than AGA children; at 6 years, SGA subjects had also a thicker aIMT and more pre-peritoneal and hepatic fat, and were less insulin sensitive (all P values between <0.05 and <0.0001). cIMT correlated positively with pre-peritoneal fat, particularly at 6 years. Post-SGA status and weight gain in early childhood (between 3 and 6 years) were independent predictors of cIMT at 6 years, explaining 48 % of its variance.

CONCLUSION

SGA children aged 3-6 years were found to have a thicker intima- media and more pre-peritoneal and hepatic fat than AGA children of comparable size.

The role of estrogen in adipose tissue metabolism: insights into glucose homeostasis regulation

Adipose tissue is an organ with active endocrine function involved in the regulation of energy balance and glucose homeostasis via multiple metabolic signaling pathways targeting the brain, liver, skeletal muscle, pancreas, and other organs. There is increasing evidence demonstrating that the female sex hormone, estrogen, regulates adipose development and improves systemic glucose homeostasis in both males and females. The underlying mechanism linking estrogenic regulation in adipose tissue and systemic glucose metabolism has not been fully elucidated, but is thought to include interactions of estrogen receptor signaling events involving lipolytic and/or lipogenic enzyme activity, free fatty acid metabolism, and adipocytokine production. Thus, understanding the effects of estrogen replacement on adipose tissue biology and metabolism is important in determining the risk of developing obesity-related metabolic disorders in patients undergoing treatment for sex hormone deficiency. In this report, we review literature regarding the role of estrogens and their corresponding receptors in the control of adipose metabolism and glucose homeostasis in both rodents and humans. We also discuss the effects of selective estrogen receptor modulators on glucose metabolism.

Low birth weight as cardiometabolic risk in Japanese high school girls

OBJECTIVE

To examine the relationships between birth weight and metabolic syndrome (MS) risk factors in healthy Japanese high school girls.

METHODS

After obtaining informed consent, we carried out health surveys for the Food Educational Program (FEP) in 2007 and 2008 in 243 healthy Japanese high school girls aged 16.4 ± 1.4 years and examined anthropometric measurements, including abdominal circumference, systolic and diastolic blood pressures (SBP and DBP, respectively), triglycerides (TG), high-density lipoprotein cholesterol (HDL), insulin, and blood glucose to calculate insulin resistance after fasting for 3 hours after lunch. Birth weight was checked by maternity record book, and food customs were recorded using a questionnaire. We analyzed the prevalence of MS risk factors by Bonferroni test following 1-way analysis of variance and their relationships with birth weight by correlation analyses.

RESULTS

According to criteria for MS risk factors in Japanese children and adults, the prevalence of obesity, high blood pressure, dyslipidemia, and high blood glucose was 7.4%, 9.1%, 7.0%, and 16.0%, respectively, and MS was detected in only 1 girl who had obesity and 2 more risks (high SBP and TG). Among 180 subjects who reported their birth weights, birth weights were significantly inversely related with SBP (p = 0.007), DBP (p = 0.033), TG (p = 0.009), insulin level (p = 0.047), insulin resistance ( p= 0.050), and number of metabolic risk factors (p = 0.022). Thirteen girls (7.2%) whose birth weights were lower than 2500 g had significantly higher SBP (p = 0.037), DBP (p = 0.032), TG (p = 0.011), insulin level (p=0.037), and insulin resistance (p = 0.043), than 31 girls (17.2%) with birth weights equal to or more than 3400 g.

CONCLUSION

The association of low birth weight could be detected to be significant with such risks of MS as SBP, DBP, TG, insulin level, and insulin resistance even in healthy Japanese high school girls, indicating the importance of follow-up and FEP for children with low birth weight for the prevention of MS in the later life.

Race- and sex-specific associations of parental education with insulin resistance in middle-aged participants: the CARDIA study

Low childhood socioeconomic status (SES) has been linked with insulin resistance (HOMA-IR) in adulthood. Our aim was to examine if maternal and paternal education, as indicators of childhood SES, equally contributed to increased HOMA-IR in later life. Of 5,115 adults from the Coronary Artery Disease Risk Development in Young Adults (CARDIA) Study aged 18-30 years in 1985-1986, data on 1,370 females and 1,060 males with baseline and 20 year follow-up data were used to estimate associations of maternal and paternal education with HOMA-IR, adjusting for personal education, BMI, lipids, blood pressure, and lifestyle factors. Parental education was determined as high with ≥ 12 years of schooling and classified as both high, only mother high, only father high, both low education. Distinct combinations of maternal and paternal education were associated with HOMA-IR across race and sex groups. Lowest year 20 HOMA-IR in European American (EA) females occurred when both parents were better educated, but was highest when only the father had better education. HOMA-IR was lowest in African American (AA) participants when the mother was better educated but the father had less education, but was highest when both parents were better educated. Parental education was unrelated to HOMA-IR in EA males. Associations of parental education with HOMA-IR are seen in AA females, AA males, and EA females but not in EA males. The distinct combinations of parental education and their associations with HOMA-IR especially in AA participants need to be addressed in further research on health disparities.

The effect of birth weight on low-energy diet-induced changes in body composition and substrate-energy metabolism in obese women

OBJECTIVE

The objective of this study was to examine the association of birth weight (BW) with body composition, resting metabolic rate (RMR), nonprotein respiratory quotient (NPRQ), and insulin sensitivity changes after a 12-week diet intervention program.

METHODS

A total of 78 obese (body mass index [BMI] 34.0 ± 2.8) women aged 36.7 ± 7 years volunteered to participate in a 12-week diet intervention program. We assessed body fat mass (FM), lean mass (LM), and bone mass (BM; measured by dual energy x-ray absorptiometry), RMR (measured by indirect calorimetry), fasting plasma glucose, and insulin before and after the intervention. We calculated BMI, FM to LM ratio (FM/LM), and HOMA-IR. BW and gestational age were self-reported, and the BW Z-score was calculated.

RESULTS

At baseline, the BW Z-score was positively associated with LM (p < 0.01) and RMR (p < 0.05). The BW Z-score was significantly associated with diet-induced FM (p < 0.05) and FM/LM ratio changes (p < 0.01) independently of potential confounders including weight loss. The BW Z-score was not associated with diet-induced RMR or insulin resistance changes.

CONCLUSIONS

Lower birth weight is associated with lower LM and RMR in obese women and could program a lower FM loss achievement after an energy-restriction diet intervention.

The Relationship between Preheparin Lipoprotein Lipase and Metabolic Derangements in Obese Japanese Children

The aim of this study was to clarify the relationship between preheparin lipoprotein lipase (LPL) and derangements of metabolic status in obese Japanese children. We examined 102 obese children (55 boys and 47 girls; mean age 10.9 yr). Anthropometry, blood pressure and levels of liver transaminases, serum lipids and lipoproteins, uric acid, fasting blood glucose (FBG), serum insulin, LPL, leptin and adiponectin were measured. The subjects were divided into the metabolic syndrome (MS) and non-MS groups. The levels of LPL were compared between these groups. Statistical analysis showed that the LPL levels were significantly lower in the MS group compared with the non-MS group, with the levels decreasing progressively as the number of MS components increased. We conclude that LPL levels decrease also in obese Japanese children with a deteriorated metabolic status in the same way as in adults.

Epidemiological studies of the developmental origins of adult health and disease in Japan: a pediatric perspective in present day Japan

The origins of adult disease are considered to relate to fetal undernutrition, and this concept is termed “developmental origins of adult health and disease” (DOHaD). Here, we describe several epidemiological studies performed in Japan and discuss whether DOHaD is applicable to children in present day Japan. In a study of healthy children and young adults, it was found that systolic blood pressure, total cholesterol and adiponectin were associated with birth weight. Hyperinsulinemia, high blood pressure, elevated transaminase levels and prevalence of metabolic syndrome in obese children were inversely correlated with birth weight and positively correlated with current weight and waist circumference. Birth weight was related to the development of type 2 diabetes in children. DOHaD is therefore considered to be applicable in Japan. The key considerations of DOHaD are the following two mismatches. The first mismatch pertains to growth and development in response to environmental influences, especially those of nutrition. The second mismatch pertains to the prenatal versus postnatal environment. We consider that the chance of children in present day Japan developing adult diseases is determined by the above mismatches. Pediatricians and schoolteachers should therefore understand the concept of DOHaD, so that they can educate both children and their families regarding an appropriate diet to reduce the likelihood of developing adult diseases in later life.

The relationship between birth weight and insulin resistance in childhood

Chronic diseases that are typical of adulthood may originate in intra-uterine life through inadequate fetal development. The present epidemiological cohort study of 506 healthy children aged 5–8 years evaluated the relationship between birth weight and insulin resistance in an age group that has been assessed in few similar studies. Insulin concentration was determined by chemiluminescence and insulin resistance by the homeostasis model assessment (HOMA). Blood glucose, total cholesterol and fractions (LDL cholesterol and HDL cholesterol) and TAG concentrations were determined by automated enzymatic methods. Linear regression analysis investigated the relationship between birth weight (assessed as a continuous variable and in three categories: small for gestational age, SGA; adequate for gestational age and large for gestational age) and the HOMA index, using backward stepwise selection and biological models to explain the causal pathway of the relationship. There were negative associations between birth weight (P < 0·001), SGA (P = 0·027) and the HOMA index, and a positive association between waist circumference (P < 0·001) and the HOMA index. Considering the significant associations between birth weight and waist circumference (P < 0·001) and waist circumference and insulin resistance (P < 0·001), we can probably suspect that lower birth weight is a common cause of higher waist circumference and insulin resistance. In summary, the results of the present study showed increased insulin resistance in apparently healthy, young children, who had lower weight at birth and higher measurements of waist circumference. There is a need to develop public health policies that adopt preventive measures to promote adequate maternal-fetal and child development and enable early diagnosis of metabolic abnormalities.

Sonographic assessment of abdominal fat distribution in infancy

There is growing evidence that not only the total amount of fat, but also the distribution of body fat determines risks for metabolic and cardiovascular disease. Developmental studies on factors influencing body fat distribution have been hampered by a lack of appropriate techniques for measuring intraabdominal fat in early life. Sonography, which is an established method for assessing abdominal fat distribution in adults, has not yet been evaluated in infants. To adapt the sonographic measurement of abdominal fat distribution to infants and study its reliability. The Generation R study, a population-based prospective cohort study. We included 212 one- and 227 two-year old Dutch infants in the present analysis. Sixty-two infants underwent replicate measurements to assess reproducibility. We developed a standardized protocol to measure the thickness of (1) subcutaneous and (2) preperitoneal fat in the upper abdomen of infants. To this end we defined infancy specific measurement areas to quantify fat thickness. Reproducibility of fat measurements was good to excellent with intraclass correlation coefficients of 0.93–0.97 for intra-observer agreement and of 0.89–0.95 for inter-observer agreement. We observed a pronounced increase in preperitoneal fat thickness in the second year of life while subcutaneous fat thickness increased only slightly, resulting in an altered body fat distribution. Gender did not significantly influence fat distribution in the first two years of life. Our age specific protocol for the sonographic measurement of central subcutaneous and preperitoneal fat is a reproducible method that can be instrumental for investigating fat distribution in early life.

Association between low birth weight and elevated white blood cell count in adulthood within a Japanese population

BACKGROUND

Epidemiological studies have demonstrated the association between low birth weight and increased adulthood risk for cardiovascular and metabolic diseases. However, the precise mechanism underlying the association remains poorly understood. We investigated the association between birth weight and adult white blood cell (WBC) count in a Japanese population.

METHODS AND RESULTS

The subjects were 779 men and 209 women aged 35-64 years. The mean WBC count was 5,283 /microl (SD: 1,326). Birth weight was divided to 6 categories: <2,500, 2,500-<2,800, 2,800-<3,000, 3,000-<3,200, 3,200-<3,500, and >3,500 g. Estimated WBC counts were 5,729, 5,341, 5,301, 5,212, 5,013 and 5,372 for the subjects with birth weights of the above respective categories (p=0.015, trend p=0.016) by one-way analysis of covariance after adjustments for sex, age, height, body mass index (BMI), lifestyles, and chronic diseases. This association was pronounced among the subjects with a BMI <25.0 kg/m2 rather than those with a higher BMI.

CONCLUSIONS

These findings support the idea that part of the association of low birth weight with elevated risk for vascular and metabolic diseases in later life could be mediated by an inflammatory pathway.

Lower birth weight is associated with higher resting heart rate during boyhood

There is substantial evidence that low birth weight is associated with the development of cardiovascular disease in adult life. Moreover, resting heart rate is a prognostic factor of cardiovascular morbidity and mortality. However, there are scarce data regarding the association between birth weight and resting heart rate in later life. Therefore, we investigated the association of anthropometric data at birth and hemodynamic indices including resting heart rate in Japanese boys. The data of 1,107 male students of a junior high school in Tokyo, Japan, who underwent a medical check-up in the year of admission to the school (12 or 13 years old) were used. Information on anthropometric data at birth based on "The Maternal and Child Health Handbook" was obtained from 573 students. From a standard 12-channel resting electrocardiogram, 8 cardiac cycles were used to estimate heart rate. Resting heart rate correlated positively with body mass index at the same age (r=0.100, p=0.017) and correlated negatively with birth weight (r=-0.102, p=0.015), height at birth (r=-0.125, p=0.003), and head circumference at birth (r=-0.095, p=0.025). The negative correlation of anthropometric data at birth with heart rate at the age of 12 or 13 was independent of body mass index at the same age. The mean value of resting heart rate at the age of 12 or 13 adjusted for body mass index at the same age was significantly higher in the lower tertile of birth weight than in the higher tertile of birth weight (81.7 vs. 78.5 beats/min, p=0.028). In conclusion, lower birth weight is associated with higher resting heart rate during boyhood, suggesting that elevated heart rate may be one mechanism linking small size at birth with the development of cardiovascular disease in future life.

Early development of visceral fat excess after spontaneous catch-up growth in children with low birth weight

CONTEXT

The sequence of prenatal growth restraint and infantile catch-up of weight is by the age of 4 yr associated with hyperinsulinemic adiposity. We studied whether the adiposity of post-catch-up children born small for gestational age (SGA) is further amplified between age 4 and 6 yr and whether visceral fat excess has already emerged by the age of 6 yr.

SETTING

The study took place at a university hospital.

STUDY POPULATION AND DESIGN

A longitudinal cohort (age 2-6 yr) of 22 children born appropriate for gestational age (AGA) and 29 born SGA were studied. Auxological, endocrine, metabolic, and body composition (by absorptiometry) assessments were made at 2, 4, and 6 yr, and visceral fat was assessed (by magnetic resonance imaging) at 6 yr.

MAIN OUTCOMES

Outcome measures included fasting glucose, insulin, IGF-I, neutrophil to lymphocyte ratio, lean mass, and total, abdominal, and visceral fat mass.

RESULTS

Between ages 4-6 yr, the relative adiposity of SGA children was further amplified. Between ages 2-6 yr, SGA children gained more total and abdominal fat and raised their insulin, IGF-I, and neutrophil to lymphocyte ratio more than did AGA children (all P<0.0001). At age 6 yr, the average amount of visceral fat was in SGA children more than 50% higher than in AGA children (P<0.005). The 0- to 2-yr increment in weight Z-score together with the 2- to 6-yr increment in fasting insulin accounted for 62% of visceral fat variability at age 6 yr.

CONCLUSION

The amount of visceral fat is in post-catch-up SGA children excessive by the age of 6 yr. In populations at risk for type 2 diabetes or metabolic syndrome after fetal growth restraint, the time window for early intervention may have to be advanced into prepubertal childhood.

Prevalence and independent predictors of insulin resistance in children from Crete, Greece: the Children Study

BACKGROUND

It has been proposed that insulin resistance (IR) is associated with the development of Type 2 diabetes mellitus and cardiovascular disease. The aim of this study is to determine the prevalence of IR in Greek schoolchildren and to investigate factors associated with IR.

METHODS

Between October 2005 and March 2006, 522 children were recruited from Crete. Physical activity and dietary habits, anthropometric and biochemical characteristics, as well as medical history of pupils' parents were recorded. IR was estimated using the homeostasis model assessment (HOMA-IR), fasting glucose-to-insulin ratio (FGIR) and quantitative insulin sensitivity check index (QUICKI). Multiple linear regression was used to determine independent predictors for IR.

RESULTS

Fasting insulin levels and HOMA-IR scores were higher in obese children and girls compared with their normal-weight peers (P < 0.001). Moreover, the former had lower values in FGIR and QUICKI indices compared with the latter, indicating that obese children and girls are more insulin resistant compared with their counterparts (P < 0.001). The prevalence of IR was 9.2% (2.9% in normal-weight, 10.5% in overweight and 31.0% in obese children), using as a threshold HOMA-IR > 2.10 97.5th percentile of normal-weight participants). Multiple linear regression revealed that central adiposity, female gender and intake of simple carbohydrates is associated positively with HOMA-IR values, even after controlling for many other factors.

CONCLUSION

These findings demonstrate that girls and obese children, particularly those with central adiposity, are at high risk of developing IR. Therefore, these groups should be targets of Type 2 diabetes mellitus and cardiovascular disease preventive interventions.

Association of obesity and visceral fat distribution with intima-media thickness of carotid arteries in middle-aged and older persons

OBJECTIVE

The association between obesity and atherosclerotic disease is controversial. We examined whether common carotid intima-media thickness (IMT), a precursor to preclinical atherosclerosis, was associated with total body fatness or the accumulation of fat mass in the abdominal region in middle-aged and older persons.

METHODS

Participants were consecutively enrolled from patients aged >or=50 years, and were 623 men aged 73+/-10 (mean+/-standard deviation) years and 835 women aged 76+/-10 years. Demographic data were collected and maximal preperitoneal fat thickness (PFT(max)) and carotid intima-media thickness (IMT) were evaluated on B-mode ultrasonography. Subjects were divided into 3 groups on the basis of body mass index (BMI), a marker of general obesity.

RESULTS

It was shown by multiple regression analysis for IMT that age, smoking status, hypertension and uric acid were significantly associated with IMT in subjects in the lowest BMI group (<20 kg/m(2)), and age, hypertension, dyslipidemia and uric acid in middle BMI group (20-22.9 kg/m(2)). Moreover, man sex, age, BMI, PFT(max), smoking status, hypertension and uric acid were significantly associated with IMT in subjects with highest BMI group (>or=23 kg/m(2)). Analysis of covariance showed that interaction between BMI and visceral obesity (f=7.202, p=0.007) was significantly associated with IMT, in addition to age, visceral obesity, smoking status, hypertension, dyslipidemia and uric acid.

CONCLUSION

The present study indicates a graded and independent association between general and visceral obesity and preclinical carotid artery changes in patients aged >or=50 years with a BMI >or=23 kg/m(2).

Aquaporin-2 water channel in developing quail kidney: possible role in programming adult fluid homeostasis

Avian kidneys have loopless and looped nephrons; a countercurrent multiplier mechanism operates in the latter by NaCl recycling. We identified an aquaporin-2 (AQP2) homolog in apical/subapical regions of cortical and medullary collecting duct (CD) cells in kidneys of Japanese quail (q), Coturnix japonica. We investigated whether undernutrition during the embryonic/maturation period retards kidney and AQP2 development in quail and programs impaired volume regulation in adults. Protocols included 1) time course and 2) effects of 5-10% egg white withdrawal (EwW) or 48-h post-hatch food deprivation (FD) on nephron growth and qAQP2 mRNA expression, and 3) effects of EwW and FD on qAQP2 mRNA responses to 72-h water deprivation in adults. In metanephric kidneys, qAQP2 mRNA is expressed in medullary CDs at embryonic day 10; distribution and intensity increase during maturation. The number and size of glomeruli continue to increase after birth, whereas nephrogenic zones decrease. In EwW embryos, qAQP2 mRNA expression is initially delayed, then restored; birth weight and hatching rate are lower than in controls. Adults from EwW embryos and FD chicks have fewer (P < 0.01) glomeruli. Water deprivation reduces body weight more in EwW birds than in controls. The results suggest that qAQP2 evolved in metanephric kidneys and that undernutrition may retard nephrogenesis, leading to impaired adult water homeostasis.

Carotid atherosclerosis in normal-weight metabolic syndrome

OBJECTIVE

To examine whether or not individuals with a normal body mass index (BMI) (18.5 kg/m(2)-24.9 kg/m(2)), but who also fulfill the criteria for the metabolic syndrome (MetS) class, can be associated with carotid atherosclerosis.

METHODS

The subjects were consecutive in-patients with a normal BMI (18.5 kg/m(2)-24.9 kg/m(2)) in the Medical Department of Seiyo Municipal Nomura Hospital enrolled between September 1996 and February 2006. The subjects were 452 men aged 69+/-15 (mean+/-standard deviation) years and 542 women aged 74+/-13 years. Carotid atherosclerosis was assessed by carotid intima-media thickness (IMT) on B-mode ultrasonography.

RESULTS

Compared with men with BMI 18.5 kg/m(2) to 20.9 kg/m(2), the odds ratios of the MetS were 2.83 (95% confidence interval [CI], 1.69-4.76) for men with BMI 21 kg/m(2) to 22.9 kg/m(2) and 6.13 (95% CI, 3.57-10.5) for men with BMI 23.0 kg/m(2) to 24.9 kg/m(2) after controlling for age, smoking status, high low-density lipoprotein cholesterol, and uric acid. Using the same regression model and BMI categories in women, the odds ratios were 2.52 (95% CI, 1.42-2.83) and 4.38 (95% CI, 2.42-7.92), respectively. Multivariate-adjusted carotid IMT was significantly greater in men with than without MetS, especially in patients with BMI 23.0 kg/m(2) to 24.9 kg/m(2). Although in women, there were no inter-group differences in categories of normal BMI and MetS.

CONCLUSION

Individuals in the upper normal BMI range have a relatively high prevalence and are at increased risk of having metabolic syndrome. Therefore, screening of individuals with normal or slightly elevated BMI is important in preventing atherosclerosis.

Metabolic Syndrome, Diabetes and Subclinical Atherosclerosis as Assessed by Carotid Intima-Media Thickness

AIM

Carotid intima-media thickness (IMT) is a useful surrogate marker of cardiovascular disease and is associated with cardiac events. We investigated cross-sectionally the association between carotid intima-media thickness (IMT), confounding risk factors, and metabolic syndrome (MetS) using the modified Japanese criteria.

METHODS

Carotid IMT was evaluated on B-mode ultrasonography in 918 patients (394 men aged 66 +/- 15 years and 524 women aged 72 +/- 13 years).

RESULTS

Among our 918 patients, 74 (8.1%) had no metabolic abnormalities, 478 (52.1%) had a metabolic abnormality with neither type 2 diabetes or MetS, and 127 had MetS without diabetes. Of the patients with type 2 diabetes, 132 (14.4%) did not have MetS and 107 (11.7%) had both type 2 diabetes and MetS. The carotid IMT values in the four groups with any metabolic abnormalities were significantly greater than the IMT of the group with neither condition (p=0.001), respectively. In syndrome model, type 2 diabetes was significantly associated with carotid atherosclerosis (p= 0.006), but MetS was borderline significant. In the component model of MetS, there was a significant association with hypertension (p<0.001) and dyslipidemia (p=0.006). Multiple logistic regression analysis for carotid atherosclerosis compared to neither condition demonstrated that subjects with both MetS and diabetes (OR, 5.58; 95% CI, 2.64-11.8), those with type 2 diabetes without MetS (OR, 3.00; 95% CI, 1.45-6.22), and those with MetS without type 2 diabetes (OR, 2.58; 75% CI, 1.24-5.39) showed a higher odds ratio after adjustment for covariates.

CONCLUSION

Even after taking into account each individual component of MetS, the clustering of visceral obesity with at least 2 of the 3 components, and diabetes are independently associated with increased carotid IMT. This suggests that the components of MetS and type 2 diabetes interact to affect vascular thickness synergistically.

Lower Birth Weight Associated with Current Overweight Status Is Related with the Metabolic Syndrome in Obese Japanese Children

The purpose of this study was to clarify the relationship between lower birth weight and current overweight status and to examine the involvement of these factors in the development of the metabolic syndrome (MS) in obese Japanese children. We examined 97 obese boys (mean age 11.3 years; mean percentage overweight [POW] 52.4%) and 29 obese girls (mean age 11.1 years; mean POW 58.3%). The anthropometric measurements, blood pressure, fasting serum insulin and blood glucose, liver enzymes, lipids and lipoproteins were measured. Birth weight and gestational weeks were also recorded. The subjects were divided into either an MS group or a Non-MS group using criteria proposed for Japanese children. We compared the weight parameters (birth weight, current weight and current weight-to-birth weight ratio [WBWR]) between the two groups and analyzed the relationships between the weight parameters and metabolic derangements. There were no significant differences in age or anthropometric measurements between the two groups. However, birth weight in the MS group was lower than that in the Non-MS group, while WBWR of the MS group was higher than that in the Non-MS group. Blood pressure and serum insulin correlated positively with WBWR. These findings suggested that lower birth weight with current overweight status was associated with the MS in obese Japanese children. We were unable to clarify whether subjects with lower birth weight who achieved proper weight gains had the same risk as subjects with appropriate birth weight. However, they should be assisted to grow adequately to prevent future metabolic derangements.