The Association between Nutrition, Physical Activity, and Cardiometabolic Health at 6 Months following a Hypertensive Pregnancy: A BP2 Sub-Study

Hypertensive disorders of pregnancy (HDP) complicate 5-10% of pregnancies, with resultant lifelong increased risks of cardiovascular disease (CVD). We aimed to describe lifestyle behaviours at 6 months post-HDP in four HDP subgroups, and their association with markers of cardiometabolic health. Subgroups were chronic hypertension (CH), gestational hypertension (GH), preeclampsia, and preeclampsia superimposed on chronic hypertension (CH + PE). The BP2 study is a multi-site, three-arm, randomised controlled trial. At 6 months postpartum, the NSW Population Health Survey and BP2 surveys collected lifestyle behaviours and demographic data. Body mass index (BMI), waist circumference, and blood pressure (BP) were also assessed. Descriptive statistics, ANOVA and Spearman's correlation coefficients were used. Of 484 women (16% CH, 23% GH, 55% preeclampsia, and 6% CH + PE), 62% were overweight or obese. Only 6% met the recommended five vegetable and two fruit serves per day, and 43% did not meet the recommended 150 min of moderate-vigorous physical activity in five sessions per week. Adherence to both diet and physical activity recommendations was correlated with more favourable cardiometabolic outcomes, including lower BMI, waist circumference, and systolic and diastolic BP. Lifestyle interventions that improve diet and physical activity post-HDP are needed to reduce BP, BMI, and long-term CVD in this high-risk population.

Optimising mothers' health behaviour after hypertensive disorders of pregnancy: a qualitative study of a postnatal intervention

Background

Hypertensive disorders of pregnancy have longer-term implications, increasing women’s lifetime cardiovascular disease risk. The Blood Pressure Postpartum study is a multi-centre randomised three-arm trial of interventions, ranging in intensity and including education and lifestyle coaching, to support women to maintain or adopt healthy eating and physical activity during the first postpartum year. This qualitative sub-study nested within the main trial aimed to investigate whether and how women adopted healthy behaviours after a pregnancy complicated by a hypertensive disorder.

Methods

Semi-structured telephone interviews were recorded, transcribed and analysed thematically, following Braun and Clarke principles. They explored behaviour change among new mothers following their hypertensive pregnancy, and the intervention’s effect on their capacity and motivation to pursue healthy lifestyles.

Results

Thirty-four women from all three trial arms participated at 10–12 months postpartum. The three main themes were 1) Awareness of cardiovascular risk: some did not acknowledge the health risks, whereas others embraced this information. 2) Sources of motivation: while the majority were motivated to make a concerted effort to adapt their health behaviour, motivation often centred on their baby and family rather than their own needs. 3) Sustaining behaviour change with a new baby: women in the more intensive intervention arm demonstrated increased recognition of the importance of reducing cardiovascular health risks, with greater motivation and guidance to change their health behaviour. There was minimal evidence of crossover amongst groups, with women largely accepting their randomised level of intervention and not seeking additional help when randomised to minimal intervention.

Conclusions

Among women participating in an early post-hypertensive disorders of pregnancy randomised controlled trial aimed at improving their cardiovascular disease risk profile, the majority recognised the future health risks and appeared motivated to improve their lifestyle, particularly women in the highest-intensity intervention group. This highlights the importance of structured support to assist women embrace healthy lifestyles especially during the challenges of new parenthood.

Trial registration

The Blood Pressure Postpartum study was prospectively registered as a clinical trial with the Australian New Zealand Clinical Trials Registry (anzctr.org.au) on 13 December 2018 (registration number: ACTRN12618002004246).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13590-2.

Blood pressure postpartum (BP2) RCT protocol: Follow-up and lifestyle behaviour change strategies in the first 12 months after hypertensive pregnancy

OBJECTIVES

Women who had hypertensive disorders of pregnancy (HDP) are twice as likely to experience maternal cardiovascular disease later in life. The primary aim of this study (BP²) is to compare outcomes of 3 different management strategies, including lifestyle behaviour change (LBC), in the first 12 months postpartum in women who had HDP in their preceding pregnancy. Secondary aims include assessing the effects on other cardiometabolic parameters.

STUDY DESIGN

Three-arm multicentre randomised trial in metropolitan Australian hospitals, (registration: ACTRN12618002004246) target sample size 480. Participants are randomised to one of three groups: 1) Optimised usual care: information package and family doctor follow-up 6 months postpartum 2) Brief intervention: information package as per group 1, plus assessment and brief LBC counselling at a specialised clinic with an obstetric physician and dietitian 6 months postpartum 3) Extended intervention: as per group 2 plus enrolment into a 6 month telephone-based LBC program from 6 to 12 months postpartum. All women have an outcome assessment at 12 months.

MAIN OUTCOME MEASURES

Primary outcomes: (a) BP change or (b) weight change and/or waist circumference change.

SECONDARY OUTCOMES

maternal health-related quality of life, engagement and retention in LBC program, biochemical markers, vascular function testing, infant weight trajectory, incremental cost-effectiveness ratios. The study is powered to detect a 4 mmHg difference in systolic BP between groups, or a 4 kg weight loss difference/2cm waist circumference change.

CONCLUSIONS

BP² will provide evidence regarding the feasibility and effectiveness of postpartum LBC interventions and structured clinical follow-up in improving cardiovascular health markers after HDP.

Zinc Intake, Zinc Bioavailability and Plasma Zinc in Obese Adolescents with Clinical Insulin Resistance Following Low Energy Diets

Background: Zinc has a critical role in metabolism and growth. This study aims to determine the effects of low-energy diets differing in macronutrient composition on zinc intake, estimated zinc bioavailability (phytate:zinc molar ratio) and plasma zinc concentration and associations between zinc status and cardiometabolic markers in obese adolescents with clinical insulin resistance (IR). Methods: Eighty-seven obese adolescents (10-17 years, body mass index z-score 2.3 ± 0.37) with clinical IR were randomized to a low-energy diet (6.0-8.0 MJ), which was either high carbohydrate or moderate carbohydrate with increased protein. Twenty-four-hour dietary recalls were collected at 6, 9 and 12 weeks. Plasma zinc concentration and cardiometabolic markers were assessed at baseline and 12 weeks. Results: Zinc intake did not differ between the 2 diet groups (p = 0.612). The high-carbohydrate group had a higher phytate intake (894 vs. 671 mg, p = 0.018) and phytate:zinc molar ratio (9.4 vs. 7.4, p = 0.009) than the increased-protein group. Plasma zinc concentration did not change from baseline in either of the diet groups, but correlated positively with zinc intake (r = 0.235, p = 0.042) and % energy from protein (r = 0.383, p = 0.001), and inversely with % energy from carbohydrate (r = -0.296, p = 0.010). Conclusions: Low energy diets for obese adolescents at risk of diabetes may need increased protein content to optimize zinc bioavailability.

Improved insulin sensitivity and body composition, irrespective of macronutrient intake, after a 12 month intervention in adolescents with pre-diabetes; RESIST a randomised control trial

Background

A higher protein to carbohydrate ratio in the diet may potentiate weight loss, improve body composition and cardiometabolic risk, including glucose homeostasis in adults. The aim of this randomised control trial was to determine the efficacy of two structured lifestyle interventions, differing in dietary macronutrient content, on insulin sensitivity and body composition in adolescents. We hypothesised that a moderate-carbohydrate (40-45% of energy), increased-protein (25-30%) diet would be more effective than a high-carbohydrate diet (55-60%), moderate-protein (15%) diet in improving outcomes in obese, insulin resistant adolescents.

Methods

Obese 10–17 year olds with either pre-diabetes and/or clinical features of insulin resistance were recruited at two hospitals in Sydney, Australia. At baseline adolescents were prescribed metformin and randomised to one of two energy restricted diets. The intervention included regular contact with the dietician and a supervised physical activity program. Outcomes included insulin sensitivity index measured by an oral glucose tolerance test and body composition measured by dual-energy x-ray absorptiometry at 12 months.

Results

Of the 111 adolescents recruited, 85 (77%) completed the intervention. BMI expressed as a percentage of the 95th percentile decreased by 6.8% [95% CI: −8.8 to −4.9], ISI increased by 0.2 [95% CI: 0.06 to 0.39] and percent body fat decreased by 2.4% [95% CI: −3.4 to −1.3]. There were no significant differences in outcomes between diet groups at any time.

Conclusion

When treated with metformin and an exercise program, a structured, reduced energy diet, which is either high-carbohydrate or moderate-carbohydrate with increased-protein, can achieve clinically significant improvements in obese adolescents at risk of type 2 diabetes.

Trial registration

Australian New Zealand Clinical Trail Registry ACTRN12608000416392. Registered 25 August 2008.

Effect of fat loss on arterial elasticity in obese adolescents with clinical insulin resistance: RESIST study

CONTEXT

Reduced arterial elasticity contributes to an obesity-related increase in cardiovascular risk in adults.

OBJECTIVE

To evaluate the effect of fat loss on arterial elasticity in obese adolescents at risk of type 2 diabetes.

DESIGN

A secondary data analysis of the RESIST study was performed in two hospitals in Sydney, Australia.

PARTICIPANTS

The study included 56 subjects (ages, 10 to 17 y; 25 males) with prediabetes and/or clinical features of insulin resistance.

INTERVENTION

A 12-month lifestyle plus metformin intervention.

OUTCOMES

Arterial elasticity and systemic vascular resistance were measured using radial tonometry pulse contour analysis, percentage body fat (%BF) was measured by dual-energy x-ray absorptiometry, and insulin sensitivity index was derived from an oral glucose tolerance test and lipids.

RESULTS

Adolescents (n = 31) with decreased %BF (mean change [range], -4.4% [-18.3 to -0.01%]) after the intervention had significant increases in the mean large arterial elasticity index (mean change [95%CI], 5.1 [1.9 to 8.2] mL/mm Hg * 10; P = .003) and insulin sensitivity index (0.5 [0.1 to 0.9]; P = .010) and a decrease in systemic vascular resistance (-82 [-129 to -35] dyne * s * cm(-5); P = .001). There were no significant changes in these parameters in adolescents who increased their %BF. Nor was there any significant change in the mean small arterial elasticity index in either group.

CONCLUSION

Long-term follow-up of these adolescents is warranted to assess whether the observed changes in vascular elasticity will lead to a clinical benefit including reduced cardiovascular morbidity and mortality.

Dietary glycemic load, insulin load, and weight loss in obese, insulin resistant adolescents: RESIST study

BACKGROUND & AIMS

The optimal dietary approach for weight loss and improving insulin sensitivity in adolescents is unknown. This study aimed to explore the association between the estimated insulin demand of the diet, as measured by glycemic and insulin load, weight loss, percentage body fat and insulin sensitivity index (ISI) in obese adolescents with clinical features of insulin resistance and/or prediabetes after a 3 month lifestyle and metformin intervention.

METHODS

Secondary data analysis of 91 adolescents (median age 12.7 years (range 10.1-17.4) participating in a randomized controlled trial, known as RESIST; ACTRN12608000416392. Weight change between baseline and 3 months was measured by BMI expressed as percentage of the 95th centile (BMI %95). Body composition was measured by dual energy X-ray absorptiometry and ISI was determined by an oral glucose tolerance test.

RESULTS

Higher dietary glycemic load and insulin load were associated with less weight loss (BMI %95), adjusted for sex and pubertal stage, β = 0.0466, P = 0.007 and β = 0.0124, P = 0.040, respectively. Inclusion of total energy intake in the model explained observed associations between dietary glycemic load and insulin load and change in BMI %95. Neither dietary glycemic load nor insulin load were associated with changes in percentage body fat or ISI. Dietary glycemic index and macronutrient content (% of total energy) were not associated to changes in BMI %95, percentage body fat or ISI.

CONCLUSION

Reduced energy diet contributes to weight loss in obese, insulin resistant adolescents. Diets with a lower insulin demand were associated with a lower energy intake and may hence assist with weight loss.

Effect of a prescriptive dietary intervention on psychological dimensions of eating behavior in obese adolescents

Background

Overweight adolescents are more likely to have dysfunctional eating behaviours compared to normal weight adolescents. Little is known about the effects of obesity treatment on the psychological dimensions of eating behavior in this population.

Objective

To examine the effects of a prescriptive dietary intervention on external eating (eating in response to food cues, regardless of hunger and satiety), emotional eating and dietary restraint and their relation to weight loss. Parental acceptability was also examined.

Method

This is a secondary study of a 12-month randomized trial, the RESIST study, which examined the effects of two diets on insulin sensitivity. Participants were 109 obese 10- to 17-year-olds with clinical features of insulin resistance. The program commenced with a 3-month dietary intervention using a structured meal plan, with the addition of an exercise intervention in the next 3 months and followed by a 6 month maintenance period.This paper presents changes in eating behaviors measured by the Eating Pattern Inventory for Children and parent rated diet acceptability during the first 6 months of the trial. As there was no difference between the diets on outcome of interest, both diet groups were combined for analyses.

Results

After 6 months, the proportion of participants who reported consuming more in response to external eating cues decreased from 17% to 5% (P = 0.003), whereas non- emotional eating increased from 48% to 65% (p = 0.014). Dietary restraint and parental pressure to eat remained unchanged. A reduction in external eating (rho = 0.36, P < 0.001) and a reduction in dietary restraint (r = 0.26, P = 0.013) were associated with greater weight loss at 3 and 6 months, respectively. Overall this approach was well accepted by parents with 72% of parents considered that their child would be able to follow the meal plan for the longer term.

Conclusions

In the short to medium term, a prescriptive dietary intervention approach is a well-accepted and suitable option for obese adolescents with clinical features of insulin resistance. It may reduce external and emotional eating, led to modest weight loss and did not cause any adverse effect on dietary restraint.

Trial registration

Australian New Zealand Clinical Trial Registration Number (ACTRN) 12608000416392 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=83071

Optimal macronutrient content of the diet for adolescents with prediabetes; RESIST a randomised control trial

CONTEXT

Prediabetes and clinical insulin resistance in adolescents are rapidly emerging clinical problems with serious health outcomes.

OBJECTIVE

The objective of this study was to determine the efficacy of 2 structured lifestyle interventions, both differing in diet macronutrient composition, on insulin sensitivity.

DESIGN

This study was a randomized controlled trial, known as Researching Effective Strategies to Improve Insulin Sensitivity in Children and Teenagers, in 2 hospitals in Sydney, Australia.

PARTICIPANTS

Participants included overweight or obese 10- to 17-year-olds with either prediabetes and/or clinical features of insulin resistance.

INTERVENTION

At baseline adolescents were prescribed metformin and randomized to a structured diet, which was either high carbohydrate or moderate carbohydrate with increased protein. The program commenced with a 3-month dietary intervention, with the addition of an exercise intervention in the next 3 months.

OUTCOMES

The outcomes included an insulin sensitivity, anthropometry, and cardiometabolic profile at 6 months.

RESULTS

One hundred eleven subjects (66 girls) were recruited and 98 subjects (58 girls) completed the 6-month intervention. After 3 months the mean insulin sensitivity index increased by 0.3 [95% confidence interval (CI) 0.2-0.4]. After 6 months the mean insulin (picomoles per liter) to glucose ratio (millimoles per liter) decreased by 7.2 [95%CI -12.0 to -2.3], body mass index, expressed as a percentage of the 95th centile, decreased by 9% (95% CI -3 to -15), but there was no significant change in the lipids. There were no significant differences in outcomes between the diet groups at any time point.

CONCLUSIONS

These results are in contrast with our hypothesis that adolescents randomized to the increased protein diet would have better outcomes. Further strategies are required to better address prediabetes and clinical features of insulin resistance in adolescents.

Genome rearrangements of bovine rotavirus after serial passage at high multiplicity of infection

After serial passage at high multiplicity of infection of standard bovine rotavirus in MA104 cells, different genome rearrangements occurred in which segment 5 was lost from the RNA profile and distinct additional bands of double-stranded (ds) RNA were found in positions on gels between segments 1 and 6. It was shown that some of the additional RNA bands contained segment 5-specific sequences. The additional RNA bands were transcribed in vitro to apparent full length. Analysis of the proteins synthesized in cells infected with viruses possessing rearranged genomes showed that in all cases the product of RNA segment 5, VP5, was missing; however, in one case an abnormal protein was observed which corresponded in size to the coding capacity of the mRNA transcribed from the additional genomic RNA band. Viruses with rearranged genomes could be plaque purified, and they grew in the absence of standard virus to titers comparable to those obtained from standard virus. In mixed infections of standard virus and virus possessing genome rearrangements, standard virus overgrew during passage at low multiplicity of infection whereas virus possessing genome rearrangements overgrew during passage at high multiplicity of infection.

Stuttering and speech naturalness: some additional data

Thirty listeners used the 9-point speech naturalness rating scale described by Martin, Haroldson, and Triden (1984) to score 1-minute spontaneous speaking samples from 15 normally fluent speakers and 15 stutterers who had completed the initial phases of a prolonged speech treatment program. The same listeners were later asked to judge whether each sample was from a stutterer or from a normal speaker. Reliable listeners identified almost identical numbers of samples from both speaker groups as "normal speakers," but the stutterers received significantly higher scores on the rating scale, indicating that their speech was judged more unnatural sounding. The speech samples incorporated those used in a related study by Ingham and Packman (1978), thus permitting a reevaluation of the findings of that study.

The role of the children's nurse in the community

In 1969 a pediatric home nursing service was started in Southampton to care for sick children at home. The primary role of the children's nurse in the community is discussed with particular reference to day case surgery, early discharge, care of the mentally and physically handicapped, pediatric medical care, prevention of a hospital admission, and care of the terminally ill. The secondary roles of teaching and liaison between the hospital and the primary health care team is discussed. After 10 yr experience with over 12,000 admissions to the day unit we believe that the majority of general surgical procedures such as circumcision, inguinal herniotomy, and orchidopexies can be safely undertaken on a day basis. The provision of adequate nursing care in the community which is closely linked with the hospital has been one of the main reasons for the success of the scheme.