Low BMI at age 20 years predicts gestational diabetes independent of BMI in early pregnancy in Japan: Tanaka Women's Clinic Study

Revisiting Regulators of Human β-cell Mass to Achieve β-cell-centric Approach Toward Type 2 Diabetes

Type 2 diabetes (T2DM) is characterized by insulin resistance and β-cell dysfunction. Because patients with T2DM have inadequate β-cell mass (BCM) and β-cell dysfunction worsens glycemic control and makes treatment difficult, therapeutic strategies to preserve and restore BCM are needed. In rodent models, obesity increases BCM about 3-fold, but the increase in BCM in humans is limited. Besides, obesity-induced changes in BCM may show racial differences between East Asians and Caucasians. Recently, the developmental origins of health and disease hypothesis, which states that the risk of developing noncommunicable diseases including T2DM is influenced by the fetal environment, has been proposed. It is known in rodents that animals with low birthweight have reduced BCM through epigenetic modifications, making them more susceptible to diabetes in the future. Similarly, in humans, we revealed that individuals born with low birthweight have lower BCM in adulthood. Because β-cell replication is more frequently observed in the 5 years after birth, and β cells are found to be more plastic in that period, a history of childhood obesity increases BCM. BCM in patients with T2DM is reduced by 20% to 65% compared with that in individuals without T2DM. However, since BCM starts to decrease from the stage of borderline diabetes, early intervention is essential for β-cell protection. In this review, we summarize the current knowledge on regulatory factors of human BCM in health and diabetes and propose the β-cell–centric concept of diabetes to enhance a more pathophysiology-based treatment approach for T2DM.

Risk of gestational diabetes mellitus in nulliparous women - Associations with early life body size and change in body mass index from childhood to adulthood

AIMS

We examined whether a woman's birthweight, childhood height, body mass index (BMI), and BMI changes from childhood to pregnancy were associated with risks of gestational diabetes mellitus (GDM).

METHODS

We studied 13,031 women from the Copenhagen School Health Records Register born 1959-1996 with birthweight and measured anthropometric information at ages 7 and/or 13. The diagnosis of GDM (n = 255) was obtained from a national health register. Risk ratios (RR) were estimated using log-linear binomial regression.

RESULTS

Own birthweight and childhood height were inversely associated with GDM. Girls with overweight at age 7 had a higher risk of GDM than girls with normal-weight (RR: 1.79, 95% CI: 1.31, 2.47). Compared to women with normal-weight in childhood and adulthood, risks of GDM were higher in women who developed overweight from age 7 to pregnancy (RR: 4.62; 3.48, 6.14) or had overweight at both times (RR: 4.71; 3.24, 6.85). In women whose BMI normalized from age 7 to pregnancy the RR for GDM was 1.08 (0.47, 2.46).

CONCLUSIONS

Lower birthweight, shorter childhood height, and higher childhood BMI are associated with increased risks of GDM. Efforts to help girls maintain a normal BMI before pregnancy may be warranted to minimize risks of GDM.

Associations of birthweight and history of childhood obesity with beta cell mass in Japanese adults

AIMS/HYPOTHESIS

Low birthweight is associated with a high risk of diabetes, but there are no reports discussing birthweight and pancreatic tissues in humans. The purpose of this study was to examine the correlation between birthweight and beta and alpha cell mass in humans.

METHODS

Sixty-four Japanese adults with and without diabetes who underwent pancreatectomy and were able to recall their weight history including birthweight were included. Pancreatic tissues were stained for insulin and glucagon, and fractional beta cell area (BCA) and alpha cell area (ACA) were quantified. Islet size and density and beta cell replication were also quantified and their associations with birthweight were evaluated.

RESULTS

In participants without diabetes, there was a weak positive correlation between birthweight and BCA (R = 0.34, p = 0.03). The group with a history of childhood obesity, but not the group with a history of obesity in adulthood only, showed higher BCA compared with those without a history of obesity (1.78 ± 0.74% vs 0.99 ± 0.53%, p = 0.01), and the correlation coefficient between birthweight and BCA increased after excluding those with a history of childhood obesity (R = 0.51, p < 0.01). In those with diabetes, there was no correlation between birthweight and BCA. No correlation was found between birthweight and ACA in either those with or without diabetes.

CONCLUSIONS/INTERPRETATION

Birthweight and beta, but not alpha, cell mass are positively correlated in non-diabetic adults, and a history of childhood obesity may affect beta cell mass. Graphical abstract.

Leaner Women with Impaired Insulin Secretion Accounts for about 40% of Gestational Diabetes Mellitus in Japan

Aim

To identify the involvement of leanness and impaired insulin secretion with Japanese gestational diabetes mellitus (GDM).

Method

A cross-sectional study was conducted comprising 219 at-risk pregnant women who underwent a 75g glucose tolerance test at a single institute in Tokyo, Japan. We identified GDM and normal glucose tolerance (NGT). The cut-off value of the homeostasis model assessment insulin resistance (HOMA-IR) for detecting GDM was determined. The GDM group was divided into subgroups according to insulin resistance based on the cut-off value of HOMA-IR. We compared the prepregnancy body mass index (BMI) and homeostasis model assessment of β-cell function (HOMA-β) between the group comprising low insulin resistance (LIR) and the group comprising high insulin resistance (HIR).

Results

Seventy GDM cases and 149 NGT cases were identified. By using receiver operating characteristic curve analysis, the HOMA-IR cut-off value was determined to be 1.41. Twenty-five GDM cases (36%) were classified as LIR and forty-five GDM cases (64%) were classified as HIR. The background including indications for having 75gOGTT and the gestational age having 75gOGTT did not differ between groups. The BMI of the LIR group was significantly lower than that of the HIR group (20.9±2.8 vs. 24.4 ± 5.5, p<0.01), and the HOMA-β of the LIR group was significantly lower than that of the HIR group (95.5±30.3 vs. 146.0±70.1, p<0.01). A positive linear correlation was found between BMI and HOMA-β in cases of GDM (r=0.27, p=0.02).

Conclusion

Leanness with impaired insulin secretion is deeply involved in Japanese gestational diabetes mellitus.

Prevalence of gestational diabetes mellitus among women attending antenatal care at public health centers in Rwanda

AIM

This study aimed to determine the prevalence of gestational diabetes mellitus (GDM) among women attending public health centers in Rwanda using the World Health Organization (WHO) 2013 diagnostic criteria.

METHODS

A cross-sectional analysis was performed on 281 pregnant women attending antenatal care at urban and rural public health centers. Diagnostic testing was performed between 24 and 32 weeks gestation using a 75 g oral glucose tolerance test. Venous plasma glucose was centrifuged within one hour and measured at one of two laboratories. Descriptive statistics were used.

RESULTS

GDM prevalence was 3.2%, (4.28% urban and 2.13% rural). Women diagnosed with GDM were older, had higher BMI, hypertension, and glycosuria of ≥2+. None with HIV (14/281) had GDM. All women reported birth outcomes. All women with GDM (9/281) had normal glucose values postpartum and therefore it is unlikely that any women had overt diabetes.

CONCLUSION

This study adds important information about the GDM prevalence in Rwanda, which is a resource-limited country. Although the prevalence of 3.2% was low, significant risk factors for GDM were identified. We anticipate that the risk factors for developing GDM will increase in the near future, similar to the global trend of obesity and diabetes, necessitating continued research and education in this important condition that carries a double burden of disease to both mothers and infants.

Being underweight in adolescence is independently associated with adult-onset diabetes among women: The Japan Nurses' Health Study

AIMS/INTRODUCTION

To examine the association between adult-onset diabetes and life-course bodyweight changes.

MATERIALS AND METHODS

In a cross-sectional study, 17,398 Japanese female nurses aged ≥30 years completed a self-administered questionnaire in 2001-2007. Bodyweight indices were calculated for three life stages: birthweight (adjusted for gestational age), body mass index (BMI) at age 18 years and current BMI. Odds ratios for being diagnosed with adult-onset diabetes were calculated according to the combined bodyweight categories of two life stages: at birth and age 18 years; and at age 18 years and the survey (current). Path analysis was carried out to decompose the effect of each bodyweight index into direct and mediating effects.

RESULTS

After adjustment for age at survey and parental diabetes history, "low" birthweight (<25th percentile), when combined with either "low" or "high" BMI (≥75th percentile) at age 18 years, had significant odds ratios (2.32, 95% confidence interval [CI] 1.22-4.44; 3.69, 95% CI 2.12-6.42, respectively) compared with the group of "middle" category (25th-74th percentile) at both life stages. The combination of "low" BMI at age 18 years and "high" current BMIs showed the highest odds ratio (7.97, 95% CI 3.97-16.00). Among women without parental diabetes history, "low" BMI at age 18 years showed a significantly high odds ratio (2.25, 95% CI 1.01-4.99), even when combined with the "middle" category of current BMI. Path analysis showed that both birthweight and BMI at age 18 years had a negative direct effect on adult-onset diabetes.

CONCLUSIONS

Underweight at adolescence, as well as overweight, is a potential risk factor for adult-onset diabetes among Japanese women.

Ethnic Disparities in Gestational Diabetes

PURPOSE OF REVIEW

Ethnicity has long been described as a major risk factor for the development of gestational diabetes mellitus (GDM), and it is widely recognised that women from ethnicities other than Europids are at higher risk of developing GDM. There are also described differences between ethnicities in key GDM pregnancy outcomes. This review describes some of the factors that relate to the ethnic disparities in GDM.

RECENT FINDINGS

The global prevalence of GDM has been steadily increasing and estimated to be 16.2% from the International Diabetes Federation extrapolation. Reported prevalence rates may understate the true prevalence, due to factors of access and attitudes to GDM diagnosis and screening in low resource settings for foreign-born women and indigenous populations. Other factors may relate to genes associated with specific ethnicities, obesity, body composition and gestational weight gain. Various factors such as access to screening, body composition, genetics and gestational weight gain may result in ethnic disparities in the prevalence and outcomes of GDM.

Carbohydrate intake during early pregnancy is inversely associated with abnormal glucose challenge test results in Japanese pregnant women

BACKGROUND

In East Asian countries, which have a high prevalence of underweight individuals, there is little information about the association between dietary factors and abnormal glucose tolerance during pregnancy. We examined the association between carbohydrate intake and moderately abnormal glucose tolerance in Japanese pregnant women.

METHODS

We conducted a prospective study on 325 Japanese pregnant women without a diagnosis of diabetes mellitus prior to pregnancy. Dietary carbohydrate intake (% of total energy intake) was assessed using a 3-day dietary record during weeks 8-15 of pregnancy. Glucose tolerance was assessed by the 50 g glucose challenge test (GCT) during weeks 24-28 of pregnancy. A positive GCT result was defined by a 1-hour plasma concentration ≥ 7.8 mmol/L. Odds ratios of a positive GCT were calculated for the top and middle tertile categories of carbohydrate intake using the bottom category as reference.

RESULTS

Mean (standard deviation) body mass index at the first prenatal visit was 19.7 (1.9) kg/m² , and 95 women were underweight. Seventy-four women had positive GCT results. Carbohydrate intake was negatively associated with a positive GCT result after adjusting for age, parity, body mass index at first prenatal visit, family history of diabetes mellitus, rate of gestational weight gain, energy intake, and dietary fiber intake (odds ratio for top category: 0.46 [95% CI, 0.23-0.93]).

CONCLUSIONS

These findings suggest that high carbohydrate intake was negatively associated with moderately abnormal glucose tolerance in a population with a high prevalence of underweight individuals.

Second trimester postload glucose level as an important predictor of low birth weight infants: Tanaka Women's Clinic Study

Although it is well known that the maternal prepregnancy BMI is a strong contributor to fetal growth, our results showed that a low postload glucose level, although within normal range, independent of maternal BMI was strongly associated with an increased risk of low birth weight births among Japanese mothers.