Survival Outcomes by Race and Ethnicity in Veterans With Nonmetastatic Castration-Resistant Prostate Cancer

Importance

Racial and ethnic disparities in prostate cancer are poorly understood. A given disparity-related factor may affect outcomes differently at each point along the highly variable trajectory of the disease.

Objective

To examine clinical outcomes by race and ethnicity in patients with nonmetastatic castration-resistant prostate cancer (nmCRPC) within the US Veterans Health Administration.

Design, Setting, and Participants

A retrospective, observational cohort study using electronic health care records (January 1, 2006, to December 31, 2021) in a nationwide equal-access health care system was conducted. Mean (SD) follow-up time was 4.3 (3.3) years. Patients included in the analysis were diagnosed with prostate cancer from January 1, 2006, to December 30, 2020, that progressed to nmCRPC defined by (1) increasing prostate-specific antigen levels, (2) ongoing androgen deprivation, and (3) no evidence of metastatic disease. Patients with metastatic disease or death within the landmark period (3 months after the first nmCRPC evidence) were excluded.

Main Outcomes and Measures

The primary outcome was time from the landmark period to death or metastasis; the secondary outcome was overall survival. A multivariate Cox proportional hazards model, Kaplan-Meier estimates, and adjusted survival curves were used to evaluate outcome differences by race and ethnicity.

Results

Of 12 992 patients in the cohort, 826 patients identified as Hispanic (6%), 3671 as non-Hispanic Black (28%; henceforth Black), 7323 as non-Hispanic White (56%; henceforth White), and 1172 of other race and ethnicity (9%; henceforth other, including American Indian or Alaska Native, Asian, Native Hawaiian or Other Pacific Islander, unknown by patient, and patient declined to answer). Median time elapsed from nmCRPC to metastasis or death was 5.96 (95% CI, 5.58-6.34) years for Black patients, 5.62 (95% CI, 5.11-6.67) years for Hispanic patients, 4.11 (95% CI, 3.96-4.25) years for White patients, and 3.59 (95% CI, 3.23-3.97) years for other patients. Median unadjusted overall survival was 6.26 (95% CI, 6.03-6.46) years among all patients, 8.36 (95% CI, 8.0-8.8) years for Black patients, 8.56 (95% CI, 7.3-9.7) years for Hispanic patients, 5.48 (95% CI, 5.2-5.7) years for White patients, and 4.48 (95% CI, 4.1-5.0) years for other patients.

Conclusions and Relevance

The findings of this cohort study of patients with nmCRPC suggest that differences in outcomes by race and ethnicity exist; in addition, Black and Hispanic men may have considerably improved outcomes when treated in an equal-access setting.

Real-world practice patterns and outcomes in Veterans with relapsed/refractory diffuse large B-cell lymphoma

Aim: To describe practices and outcomes in veterans with relapsed/refractory diffuse large B-cell lymphoma. Patients & methods: Using Veteran Affairs Cancer Registry System and electronic health record data, we identified relapsed/refractory diffuse large B-cell lymphoma patients completing second-line treatment (2L) in 2000–2016. Treatments were classified as aggressive/nonaggressive. Analyses included descriptive statistics and the Kaplan–Meier estimation of progression-free survival and overall survival. Results: Two hundred and seventy patients received 2L. During median 9.7-month follow-up starting from 2L, 470 regimens were observed, averaging 2.7 regimens/patient: 219 aggressive, 251 nonaggressive. One hundred and twenty-one patients proceeded to third-line, 50 to fourth-line and 18 to fifth-line treatment. Median progression-free survival in 2L was 5.2 months. Median overall survival was 9.5 months. Forty-four patients (16.3%) proceeded to bone marrow transplant. Conclusion: More effective, less toxic treatments are needed and should be initiated earlier in treatment trajectory.

Maintenance rituximab in Veterans with follicular lymphoma

Real-world practice patterns and clinical outcomes in patients with follicular lymphoma (FL), including the adoption of maintenance rituximab (MR) therapy in the United States (US), have been reported in few studies since the release of the National LymphoCare Study almost a decade ago. We analyzed data from the largest integrated healthcare system in the United States, the Veterans Health Administration (VHA), to identify rates of adoption and effectiveness of MR in FL patients after first-line (1L) treatment. We identified previously untreated patients with FL in the VHA between 2006 and 2014 who achieved at least stable disease after chemoimmunotherapy or immunotherapy. Among these patients, those who initiated MR within 238 days of 1L composed the MR group, whereas those who did not were classified as the non-MR group. We examined the effect of MR on progression-free survival (PFS) and overall survival (OS). A total of 676 patients met our inclusion criteria, of whom 300 received MR. MR was associated with significant PFS (hazard ratio [HR]=0.55, P < .001) and OS (HR = 0.53, P = .005) compared to the non-MR group, after adjusting by age, sex, ethnicity, geographic region, diagnosis period, stage, grade at diagnosis, hemoglobin, lactate dehydrogenase (LDH), Charlson comorbidity index (CCI), 1L treatment regimen, and response to 1L treatment. These results suggest that in FL patients who do not experience disease progression after 1L treatment in real-world settings, MR is associated with a significant improvement in both PFS and OS. Maintenance therapy should be considered in FL patients who successfully complete and respond to 1L therapy.

Abstract 3505: Opioid use in Veterans with metastatic castration-resistant prostate cancer

Rationale: Describe the real-world practice patterns of opioids in Veterans with metastatic castration-resistant prostate cancer.

Background: Pain is one of the most common and debilitating symptoms of metastatic castration-resistant prostate cancer (mCRPC); it is associated not only with decreased quality of life but also shorter overall survival. Current guidelines recommend opioid therapy for alleviating pain in adult cancer patients, however, administration of opioids may have adverse effects including constipation, nausea, and respiratory depression. Previous studies have reported that long-term use of opioids in advanced cancer patients may contribute to increased healthcare utilization, morbidity, and mortality.6 However, few studies have examined the use of opioids in patients with advanced prostate cancer. This study examines current opioid practice patterns in mCRPC patients treated in the Veterans Health Administration (VHA).

Methods: Patient information from the Veterans Affairs (VA) Central Registry System and the VA Corporate Data Warehouse was used to identify patients who were diagnosed with prostate cancer and later developed mCRPC, defined as (1) radiologic evidence of metastasis obtained from radiology reports using a natural language processing algorithm; (2) evidence of rising prostate-specific antigen (PSA); (3) evidence of ongoing androgen deprivation consisting of a serum testosterone level of ≤ 50 ng/dL. Patient demographics, disease characteristics, treatment practices, and survival outcomes were extracted and have been previously presented. Opioid medications (including both oral and intravenous) used during 1L treatment were identified and included codeine, fentanyl, hydromorphone, methadone, morphine, oxycodone, tramadol, and hydrocodone.

Results: From 2006 to 2015, 120,374 patients were diagnosed with and treated for prostate cancer in the VHA, with 3,637 developing mCRPC. Of these patients 1,590 (44%) patients received first-line (1L) therapy, 1,143 (31%) received second-line (2L) therapy, and 590 (16%) received third-line (3L) therapy. The most frequently used treatments, regardless of treatment line were abiraterone, docetaxel, and enzalutamide. All mCRPC patients (1,590, 100%)–regardless of therapy–were treated with at least one opioid during their disease course. The opioids most frequently prescribed opioids during 1L therapy included: oxycodone (686, 43%), hydrocodone (679, 43%), and morphine (661, 42%). During 2L therapy morphine (361, 32%) became the most frequently used opioid, followed by oxycodone (352, 31%) and hydrocodone (287, 25%). Morphine (192, 33%), oxycodone (165, 28%), and hydrocodone (145, 25%) were the most frequently used opioids during 3L therapy.

Discussion: Our findings suggest there is high utilization of opioids in mCRPC patients treated in the VHA. Further efforts will examine whether opioid use impacts overall survival in Veterans with advanced prostate cancer.

Conclusions: There is a significant need for determining the most appropriate method of integrating opioid therapy to reduce pain in patients with mCRPC.

Citation Format: Kelli M. Rasmussen, Christina Yong, Vikas Patil, Catherine Li, Brian C. Sauer, Ahmad Halwani. Opioid use in Veterans with metastatic castration-resistant prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3505.

Atrial Fibrillation and Bleeding in Patients With Chronic Lymphocytic Leukemia Treated with Ibrutinib in the Veterans Health Administration

BACKGROUND

Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in adults. The introduction of novel oral agents, starting with ibrutinib in 2013, has revolutionized the therapeutic landscape; however, clinical trials have suggested an association between ibrutinib and the risk of bleeding-related adverse events and atrial fibrillation (Afib) in patients with CLL.

METHODS

Patients diagnosed and treated for CLL at the Veterans Health Administration (VHA) from 2010 to 2014 were followed until December 31, 2016, death, or lack of utilization of hematology/oncology services for ≥ 18 months; or until incidence of another cancer. Treatments dispensed, evidence of VHA system use, bleeding events, and Afib were determined from the administrative records, laboratory records, pharmacy dispensation records, and clinical notes in the electronic healthcare record.

RESULTS

From 2010 to 2014, 2,796 patients were diagnosed and received care for CLL within the VHA, of whom 172 patients received ibrutinib and 291 received bendamustine + rituximab (BR). The use of anticoagulants following induction therapy did not differ between BR and ibrutinib patients (9% vs 8%, respectively), nor did the use of antiplatelets agents (6% vs 2%, respectively). Of the 291 patients that received BR, 12 (4%) developed a bleeding event compared with 20 (12%) who received ibrutinib. Additionally, 13 (8%) ibrutinib patients developed Afib compared with 9 (3%) BR patients.

CONCLUSIONS

Real-world evidence from a nationwide cohort of patients with CLL suggests that while ibrutinib is associated with increased bleeding-related adverse events and Afib, the risk is comparable to those reported in previous clinical trials. These findings suggest that patients in real-world clinical care settings with higher levels of comorbidities may be at an increased risk for bleeding events and Afib.

Real-world practice patterns in veterans with metastatic castration-resistant prostate cancer

BACKGROUND

Metastatic castration-resistant prostate cancer (mCRPC) is incurable, with most patients surviving less than 3 years. However, many treatments that extend survival have been approved in the past decade.

OBJECTIVE

To describe the patient demographics, disease characteristics, treatment patterns, and outcomes in a cohort of Veterans diagnosed with mCRPC in the Veterans Health Administration.

DESIGN

We identified 3,637 Veterans diagnosed with prostate cancer between January 2006 and August 2015 with evidence of mCRPC through December 2016. We described the most commonly used systemic mCRPC treatments according to mCRPC diagnosis era: Epoch 1 (2006-2010) or Epoch 2 (2011-2016). Patient demographics, disease characteristics, and treatment patterns were examined using descriptive statistics. An unadjusted Kaplan-Meier method was used to estimate the median time to biochemical progression and overall survival (OS) with 95% confidence intervals.

RESULTS

The median age at initial prostate cancer diagnosis was 68 years. Approximately 67% of patients were non-Hispanic white, 29% were black, and 4% were other/unknown. A high-risk Gleason score (8-10) was reported in 748 (67%) of patients in Epoch 1 and 1578 (63%) of patients in Epoch 2, and the median prostate-specific antigen level at initial prostate cancer diagnosis was higher in Epoch 1 patients than in Epoch 2 patients (68 vs. 35 ng/ml). Following mCRPC diagnosis, the most common first-line therapies in Epoch 1 patients were docetaxel (83%) and abiraterone (9%), whereas Epoch 2 patients mainly received abiraterone (47%), docetaxel (36%), and enzalutamide (15%). In Epoch 1 and Epoch 2 patients, the median time to biochemical progression (unadjusted) was 9 and 13 months, respectively, and the median OS (unadjusted) was 15 and 23 months, respectively.

CONCLUSIONS

The introduction of new therapies has resulted in increased use of the noncytotoxic agents abiraterone and enzalutamide as first-line treatment in lieu of docetaxel. Our results suggest that more recently diagnosed patients (Epoch 2) have a delayed time to biochemical progression and longer OS (unadjusted) compared with patients diagnosed earlier (Epoch 1).

Abstract 3309: Healthcare resource utilization in follicular lymphoma patients treated with maintenance rituximab in the Veterans Health Administration

OBJECTIVES: Examine healthcare resource utilization (HCRU) in follicular lymphoma (FL) patients treated with or without maintenance rituximab (MR).

METHODS: FL patients treated in the Veterans Health Administration (VHA) between 2006-2014 were identified by linking information from the VA Cancer Registry System (VACRS) and the Corporate Data Warehouse. HCRU was defined as the total number of outpatient visits (OPV), inpatient visits (IPV), and the number of emergency department visits (EDV) during follow-up time, which was approximately four years. To avoid immortal time bias, a prescription time distribution matching method was performed, followed by an inverse probability weighted regression analysis to account for variation in the follow-up period. The observational period was partitioned into four-yearly intervals. The observed HCRU value was weighted by the inverse of the probability of not being censored by the end of the yearly interval. A generalized linear model with Poisson distribution and log link was performed for each of the four intervals while adjusting for the covariates. Using a 95% bootstrap confidence interval, the change of HCRU was summed across the four-yearly intervals to obtain the cumulative change of HCRU between FL patients who received MR or did not receive MR.

RESULTS: From 2006-2014, 2,290 FL patients were diagnosed at VHA. After excluding patients with a prior cancer, documented grade 3b or stage I disease, 905 MR-eligible patients remained, of which 319 (35%) received MR and 586 (65%) did not receive MR. When compared with non-MR patients, MR patients were slightly more likely to have a mean increase in OPV (0.69%; CI: 0.44%-0.94%) and a mean decrease in IPV (14.83%; CI: 16.09%-13.58%). There was no significant change in the number of EDV between the MR treated and non-MR treated patients.

CONCLUSIONS: This nationwide real-world study suggests that on average FL patients treated with MR have fewer IPV and more OPV than non-MR patients.

Note: This abstract was not presented at the meeting.

Citation Format: Ahmad S. Halwani, Catherine Li, Kelli M. Rasmussen, Vikas Patil, Christina Yong, Zachary Burningham, Brian C. Sauer. Healthcare resource utilization in follicular lymphoma patients treated with maintenance rituximab in the Veterans Health Administration [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3309.

Summary of Veterans Health Administration Cancer Data Sources

OBJECTIVES

The Veterans Health Administration (VHA) is a leader in generating transformational research across the cancer care continuum. Given the extensive body of cancer-related literature utilizing VHA data, our objectives are to: (1) describe the VHA data sources available for conducting cancer-related research, and (2) discuss examples of published cancer research using each data source.

METHODS

We identified commonly used data sources within the VHA and reviewed previously published cancer-related research that utilized these data sources. In addition, we reviewed VHA clinical and health services research web pages and consulted with a multidisciplinary group of cancer researchers that included hematologist/oncologists, health services researchers, and epidemiologists.

RESULTS

Commonly used VHA cancer data sources include the Veterans Affairs (VA) Cancer Registry System, the VA Central Cancer Registry (VACCR), the Corporate Data Warehouse (CDW)-Oncology Raw Domain (subset of data within the CDW), and the VA Cancer Care Cube (Cube). While no reference standard exists for cancer case ascertainment, the VACCR provides a systematic approach to ensure the complete capture of clinical history, cancer diagnosis, and treatment. Like many population-based cancer registries, a significant time lag exists due to constrained resources, which may make it best suited for historical epidemiologic studies. The CDW-Oncology Raw Domain and the Cube contain national information on incident cancers which may be useful for case ascertainment and prospective recruitment; however, additional resources may be needed for data cleaning.

CONCLUSIONS

The VHA has a wealth of data sources available for cancer-related research. It is imperative that researchers recognize the advantages and disadvantages of each data source to ensure their research questions are addressed appropriately.

Breastfeeding and later maternal risk of hypertension and cardiovascular disease - The role of overall and abdominal obesity

In this study, we examined how any, full, and partial breastfeeding durations were associated with maternal risk of hypertension and cardiovascular disease (CVD), and how prepregnancy body mass index (BMI) and waist circumference 7 years postpartum influenced these associations. A total of 63,260 women with live-born singleton infants in the Danish National Birth Cohort (1996-2002) were included. Interviews during pregnancy and 6 and 18 months postpartum provided information on prepregnancy weight, height, and the duration of full and partial breastfeeding. Waist circumference was self-reported 7 years postpartum. Cox regression models were used to estimate hazard ratios of incident hypertension and CVD, registered in the National Patient Register from either 18 months or 7 years postpartum through 15 years postpartum. Any breastfeeding ≥4 months was associated with 20-30% lower risks of hypertension and CVD compared to <4 months in both normal/underweight and overweight/obese women. At follow-up starting 7 years postpartum, similar risk reductions were observed after accounting for waist circumference adjusted for BMI. Partial breastfeeding >2 months compared to ≤2 months, following up to 6 months of full breastfeeding, was associated with 10-25% lower risk of hypertension and CVD. Compared with short breastfeeding duration, additional partial breastfeeding was as important as additional full breastfeeding in reducing risk of hypertension and CVD. Altogether, longer duration of breastfeeding was associated with lower maternal risk of hypertension and CVD irrespective of prepregnancy BMI and abdominal adiposity 7 years after delivery. Both full and partial breastfeeding contributed to an improved cardiovascular health in mothers.

Abstract A055: Racial disparities in metastatic castrate-resistant prostate cancer (mCRPC): Evidence from the Veterans Health Administration (VHA)

Purpose: Describe patients, disease characteristics, and treatment patterns of a nationwide cohort of black men with mCRPC in the largest nationwide integrated health care system in the United States: the VHA.

Background: Black men have an increased incidence of prostate cancer, are diagnosed at an earlier age than white men with similar demographic and disease characteristics, and experience worse clinical outcomes (1–4). This study examines disease characteristics and treatment practices among black men with mCRPC over a 10-year period for the first 2 lines of therapy in the VHA.

Methods: Patient information was obtained from the Veterans Affairs (VA) Clinical Cancer Registry (VACCR) and the VA Corporate Data Warehouse (CDW) to identify patients who were diagnosed with prostate cancer at the VA and later developed mCRPC, defined as: (1) radiologic evidence of metastasis obtained from radiology reports using a natural language processing algorithm (5); (2) evidence of rising prostate-specific antigen (PSA), i.e., 2 consecutive increases in the PSA concentration over a baseline value, retrieved from the CDW/ VA Informatics and Computing Infrastructure (VINCI) Lab Chemistry package using the Clinical Lab Information Retrieval (CLIR) (6); (3) evidence of ongoing androgen deprivation consisting of a serum testosterone level of ≤ 50 ng/dL (≤ 2.0 nmol/L), retrieved from the CDW/ VINCI Lab Chemistry package using the CLIR pipeline, whereby the values were extracted based on the LOINC code and/or lab test name. Treatments of mCRPC were identified by review of the NCCN Prostate Cancer Guidelines V2.2017. Therapies were extracted from CDW pharmacy dispensation records (docetaxel, abiraterone, enzalutamide, etc.). Race/ethnicity data were obtained from VACCR. Classification of race/ethnicity using VA data was previously validated by Kressin et al (7). Charlson Comorbidity Index (CCI) was calculated using Quan comorbidity mapping (8).

Results: 120,374 patients were diagnosed with prostate cancer and treated in the VA from 2006 to 2016; of these, 3,637 developed mCRPC, of whom 2,429 (67%) were white, 1,066 (29%) were black, and 142 (4%) were reported as other. Compared with white men, at diagnosis black men were younger (66 vs. 69 years) and had a higher PSA (92.25 ng/mL vs. 41 ng/mL). Disease characteristics at diagnosis were comparable: Gleason 2-6 (1% vs. 1%), 7 (19% vs. 22%), 8-10 (66% vs. 63%); Stages II (28% vs. 32%), III (5% vs. 4%), IV (61% vs. 60%). Treatment did not differ significantly: radiation (26% vs. 26%), prostatectomy (6% vs. 4%), surgical orchiectomy (2% vs. 1%), castration by agonists (85% vs. 86%), castration by agonists/androgen deprivation (34% vs. 33%). Cytotoxic agent docetaxel was the primary first-line therapy for both black and white men (28% and 27%). More white men received first-line abiraterone acetate (AA; 22%) compared with black men (19%), although more black men than white men received second-line AA (17% vs. 14%). Similar treatment patterns between black and white men were observed when the results were further stratified by time period (2006-2010 vs. 2011-2016).

Conclusions: This is the first study of a large, nationwide, contemporary cohort of black men with mCRPC treated in an integrated equal-access health care system, the VHA. Consistent with prior reports, black men with mCRPC were younger and had higher PSA values, although treatment patterns between the 2 groups were similar.

References:

1. DeSantis CE, et al. CA Cancer J Clin 2016;66:290-308.

2. Robbins AS, et al. Am J Epidemiol 2007;166:71-8.

3. Moul JW, et al. J Urol 1996;155:1667-73.

4. Tsodikov A, et al. Cancer 2017;123:2312-2319.

5. Chapman WW, et al. J Biomed Inform 2001;34:301-10.

6. Halwani A, et al. VAAHO 2016 [abstract 41].

7. Kressin NR, et al. Am J Public Health 2003;93:1734-9.

8. Quan H, et al. Med Care 2005;43:1130-9.

Citation Format: Ahmad Halwani, Kelli M. Rasmussen, Vikas Patil, Zachary Burningham, Sujata Narayanan, Shih-Wen Lin, Susheela Carroll, Ling-I Hsu, Julie N. Graff, Robert Dreicer, Sumati Gupta, Clarke Low, Brian C. Sauer. Racial disparities in metastatic castrate-resistant prostate cancer (mCRPC): Evidence from the Veterans Health Administration (VHA) [abstract]. In: Proceedings of the AACR Special Conference: Prostate Cancer: Advances in Basic, Translational, and Clinical Research; 2017 Dec 2-5; Orlando, Florida. Philadelphia (PA): AACR; Cancer Res 2018;78(16 Suppl):Abstract nr A055.

Is Cancer Protective for Subsequent Alzheimer's Disease Risk? Evidence From the Utah Population Database

OBJECTIVE

Several studies have suggested that cancer is associated with a reduced risk of the development of Alzheimer's disease (AD). This study seeks to improve our understanding of the association between cancer and the development of AD by showing how mortality selection alters this relationship.

METHOD

A retrospective cohort study was carried out examining 92,425 individuals (47,873 women and 44,552 men) from the Utah Population Database with and without a history of any primary cancer identified by the Utah Cancer Registry. All individuals were aged 65-79 years and free of dementia in 1992 and followed for upwards of 18 years (1992-2009) for AD ascertainment, which was identified using diagnostic information from Medicare claims data.

RESULTS

We replicate previous results suggesting that cancer is associated with reduced risk of subsequent AD under specific statistical model specifications. However, these results should not be interpreted as evidence of an etiological association. We conclude that higher rates of overall mortality among individuals with cancer relative to those without cancer induce the widely reported putative protective association with cancer.

CONCLUSION

Careful consideration of model specification and the profound effects of mortality selection in the older adult population is essential when investigating the relationship between aging-related diseases such as cancer and AD. We show that cancer does not provide protection from AD as previously described in the literature. Social scientists seeking to understand social disparities in disease outcomes among older adults may therefore want to strongly consider the role of mortality selection which, if uncorrected, may generate biased associations.

Amyloid Positivity Using [18F]Flutemetamol-PET and Cognitive Deficits in Nondemented Community-Dwelling Older Adults

Little research exists examining the relationship between beta-amyloid neuritic plaque density via [18F]flutemetamol binding and cognition; consequently, the purpose of the current study was to compare cognitive performances among individuals having either increased amyloid deposition (Flute+) or minimal amyloid deposition (Flute-). Twenty-seven nondemented community-dwelling adults over the age of 65 underwent [18F]flutemetamol amyloid-positron emission tomography imaging, along with cognitive testing using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and select behavioral measures. Analysis of variance was used to identify the differences among the cognitive and behavioral measures between Flute+/Flute- groups. Flute+ participants performed significantly worse than Flute- participants on RBANS indexes of immediate memory, language, delayed memory, and total scale score, but no significant group differences in the endorsed level of depression or subjective report of cognitive difficulties were observed. Although these results are preliminary, [18F]flutemetamol accurately tracks cognition in a nondemented elderly sample, which may allow for better prediction of cognitive decline in late life.

Relationship between 18F-Flutemetamol uptake and RBANS performance in non-demented community-dwelling older adults

OBJECTIVE

The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) has been used extensively for clinical care and in research for patients with mild cognitive impairment and Alzheimer's disease (AD); however, relatively few studies have evaluated the relationship between RBANS performance and AD imaging biomarkers. The purpose of the current study was to evaluate the association between a relatively new amyloid positron emission tomography imaging biomarker and performance on the RBANS.

METHODS

Twenty-seven nondemented community-dwelling adults over the age of 65 underwent ¹⁸F-Flutemetamol amyloid- positron emission tomography imaging, along with cognitive testing using the RBANS and select behavioral measures. Partial correlation coefficients were used to identify relationships between the imaging and behavioral markers.

RESULTS

After controlling for age and education, amyloid deposition and RBANS Indexes of Immediate Memory, Delayed Memory, and Total Scale score were significantly correlated (p's < .001, r's = -.73 to -.77, d's = 2.13-2.39), with greater amyloid burden being associated with lower RBANS scores. The Delayed Memory Index was particularly highly associated with ¹⁸F-Flutemetamol binding (r² = .59, p < .001, d = 2.39). Neither ¹⁸F-Flutemetamol binding nor RBANS performance was significantly correlated with levels of depression, subjective cognitive difficulties, or premorbid intellect.

CONCLUSIONS

Because of the limited use of amyloid imaging in clinical settings due to high cost and lack of reimbursement, these findings suggest that in particular RBANS Delayed Memory Index may be a cost-efficient tool to identify early signs of AD pathology, and its use may enlighten clinical decision-making regarding potential progression to dementia due to AD.

Effects of body size and change in body size from infancy through childhood on body mass index in adulthood

BACKGROUND

Weight and weight gain throughout infancy are related to later obesity, but whether the strength of the associations varies during the infancy period is uncertain.

AIMS

Our aims were to identify the period of infancy when change in body weight has the strongest association with adult body mass index (BMI) and also the extent to which these associations during infancy are mediated through childhood BMI.

METHODS

The Copenhagen Perinatal Cohort, in which participants were followed from birth through 42 years of age, provided information on weight at 12 months and BMI at 42 years for 1633 individuals. Information on weight at birth, 2 weeks, 1, 2, 3, 4 and 6 months was retrieved from health visitors' records and information on BMI at ages 7 and 13 years from school health records. The associations of infant weight and weight gain standard deviation scores (SDS) with adult BMI-SDS were analyzed using multiple linear regression and path analysis.

RESULTS

Higher-weight-SDS at all ages from birth to an age 12 months were associated with higher-BMI-SDS at 42 years (regression coefficients 0.08-0.12). Infant weight gain-SDS was associated with greater BMI-SDS at 42 years only between birth and 3 months (0.09, 95% confidence intervals (CI) 0.04, 0.15) driven by an association between 2 and 3 months (0.12, 95% CI: 0.04, 0.20). The latter was partly mediated through later BMI in the path analysis. Infant weight gain-SDS between 3 and 12 months was not associated with greater BMI-SDS at 42 years.

CONCLUSIONS

Faster weight gain during only the first 3 months of infancy was associated with increased adult BMI, although not in a consistent monthly pattern. Adult BMI is more sensitive to high weight gain during early infancy than late infancy, but not specifically to the first month of life.

Prediction of excessive gestational weight gain from week-specific cutoff values: a cohort study

OBJECTIVE

To assess the prognostic validity of the Institute of Medicine/National Research Council (IOM/NRC) week-specific cutoff values for inadequate or excessive total gestational weight gain (GWG) by 4-week intervals.

STUDY DESIGN

We merged data from two German cohorts (LMU cohort (all maternal-weight categories) and PEACHES cohort (obese women)) to provide information on GWG for 749 women (365 normal weight, 199 overweight and 185 obese). We calculated the prognostic values for suboptimal and excessive GWG according to the IOM/NRC cutoff values.

RESULT

The positive predictive values for excessive total GWG for those who experienced excessive GWG early in pregnancy was 70.1% (95% confidence interval (CI) 60.5; 78.6) as of week 12/1 to 16/0 in normal-weight women, 89.5% (95% CI 75.2; 97.1) and 95.2 (76.2; 99.9) 95.2% (95% CI 76.2; 99.9) as of week 8/1 to 12/0 for overweight and obese women, respectively. In absence of excessive GWG as of week 12/1 to 16/0, normal-weight women had 77.5% (95% CI 77.1; 83.1) probability of not experiencing excessive total GWG (negative predictive value). In overweight and obese women, the negative predictive value was considerably lower up to week 24/1 to 28/0 (60.0% (95% CI 48.8; 70.5) in week 20/1 to 24/0 and 50.6% (95% CI 39.3; 61.9) in week 24/1 to 28/0). Most women with inadequate GWG in the first and second trimester had adequate total final GWG (positive predictive value for total inadequate GWG <50% up to week 16/1 to 20/0 in all groups).

CONCLUSION

As women with excessive weight gain can be identified with high confidence if the GWG exceeds the IOM/NRC week-specific cutoff values, interventions may be initiated early in pregnancy.

Household food security is associated with early childhood language development: results from a longitudinal study in rural Bangladesh

BACKGROUND

Although household food security (HHFS) has been linked to academic performance in school children, its association with early childhood development has received less attention, particularly in low-income countries. We investigated the association of HHFS with subsequent language development of children at 18 months of age in rural Bangladesh.

METHODS

We followed 1439 infants born in 2002-2003 to the mothers in Maternal and Infant Nutrition Intervention in Matlab study, a large intervention trial conducted in rural Bangladesh. A HHFS scale was created from data collected from mothers during pregnancy. At 18 months, children's language (expression and comprehension) development was assessed using a Bengali adaptation of MacArthur's Communicative Development Inventory which was based on mothers' report of their children's ability to comprehend and express words in different categories. General linear regression models were used to examine the association between HHFS and language development at 18 months of age adjusting for potential confounders.

RESULTS

Household food security was associated with language comprehension (B = 0.19, 95% CI = 0.09, 0.30, P < 0.001) and expression (B = 1.01, 95% CI = 1.00, 1.02, P < 0.01) at 18 months of age. Mean language comprehension and expression at 18 months of the children in higher quartiles of HHFS were higher (P < 0.05) than those of the children in lower quartiles.

CONCLUSIONS

Household food security is positively associated with subsequent language development of rural Bangladeshi children. Early language development has been reported to predict later child development. Therefore, strategies to ensure HHFS status in Bangladesh and similar settings should be considered for optimum child development.

Maternal energy depletion is buffered among malnourished women in Punjab, Pakistan

Women's nutritional status is believed to deteriorate with increasing reproductive stress (so-called maternal depletion). To evaluate this phenomenon, a new theoretical framework has been suggested that incorporates the concepts of a full reproductive cycle, relative lengths of potential depletion and repletion phases, and initial plane of nutrition. We developed the corresponding statistical model and tested predictions provided by the framework about the effect of reproductive pattern on maternal overall weight change (deltaW) during one reproductive cycle. Seventy-six Pakistani women were classified as well-nourished, marginally nourished or malnourished. The relationship between deltaW and length of all phases of the reproductive cycle, each of which is characterized by varying degrees of reproductive stress, was evaluated with multiple regression analysis. Across the reproductive cycle, well-nourished women had a slight weight increase. Surprisingly, malnourished women gained weight in contrast to marginally nourished women. Also surprisingly, for the latter two groups, periods of moderate reproductive stress were associated with weight loss but periods of high reproductive stress were associated with weight gain. Mechanisms such as efficiency and nutrient partitioning are discussed.

The nutritional phenotype in the age of metabolomics

The concept of the nutritional phenotype is proposed as a defined and integrated set of genetic, proteomic, metabolomic, functional, and behavioral factors that, when measured, form the basis for assessment of human nutritional status. The nutritional phenotype integrates the effects of diet on disease/wellness and is the quantitative indication of the paths by which genes and environment exert their effects on health. Advances in technology and in fundamental biological knowledge make it possible to define and measure the nutritional phenotype accurately in a cross section of individuals with various states of health and disease. This growing base of data and knowledge could serve as a resource for all scientific disciplines involved in human health. Nutritional sciences should be a prime mover in making key decisions that include: what environmental inputs (in addition to diet) are needed; what genes/proteins/metabolites should be measured; what end-point phenotypes should be included; and what informatics tools are available to ask nutritionally relevant questions. Nutrition should be the major discipline establishing how the elements of the nutritional phenotype vary as a function of diet. Nutritional sciences should also be instrumental in linking the elements that are responsive to diet with the functional outcomes in organisms that derive from them. As the first step in this initiative, a prioritized list of genomic, proteomic, and metabolomic as well as functional and behavioral measures that defines a practically useful subset of the nutritional phenotype for use in clinical and epidemiological investigations must be developed. From this list, analytic platforms must then be identified that are capable of delivering highly quantitative data on these endpoints. This conceptualization of a nutritional phenotype provides a concrete form and substance to the recognized future of nutritional sciences as a field addressing diet, integrated metabolism, and health.

Metabolomics in the opening decade of the 21st century: building the roads to individualized health

It is rapidly becoming possible to measure hundreds or thousands of metabolites in small samples of biological fluids or tissues. This makes it possible to assess the metabolic component of nutritional phenotypes and will allow individualized dietary recommendations. ASNS has to take action to ensure that appropriate technologies are developed and that metabolic databases are constructed with the right inputs and organization. The relations between diet and metabolomic profiles and between those profiles and health and disease must be established. ASNS also should consider the social implications of these advances and plan for their appropriate utilization.

Associations between reproduction and maternal body weight: examining the component parts of a full reproductive cycle

OBJECTIVE

Many transitional societies currently face both extremes of nutritional status, undernutrition and overnutrition. Women of reproductive age are at high risk of these conditions. The purpose of this review is to consider evidence for relationships between reproduction and nutritional status in women from societies of varying economic development, using body weight or weight-for-height as indicators of maternal nutritional status.

DESIGN

The conceptual framework guiding this review is that the duration of the reproductive cycle varies as a function of its component parts, which include (i) pregnancy, (ii) lactation, (iii) the non-pregnant/non-lactating (NP/NL) interval or, possibly, (iv) an overlap between lactation and next pregnancy. All component parts of the complete cycle vary in length and are associated with changes in nutritional status. A variety of factors ('proximal and distal determinants') influence the duration of the component parts of the reproductive cycle. This framework is used to examine current knowledge of changes in maternal nutritional status during each of these parts.

RESULTS

Women in affluent societies retain some weight with each pregnancy, beyond that of non-pregnant women. Women in less affluent societies retain less weight with each pregnancy. During lactation, women in both affluent and less affluent societies experience only modest weight loss. During the NP/NL interval, women in affluent societies tend to gain weight, whereas weight of women in less affluent societies is likely to fluctuate.

CONCLUSIONS

We conclude that there is a dearth of information on certain parts of the cycle, particularly the periods of overlap of lactation with pregnancy and the NP/NL interval.

A low-fat diet but not food restriction improves lactational performance in obese rats

Rats fed a high-fat diet before and during lactation have difficulty initiating lactation and have high pup mortality rates, low milk production and, consequently, poor pup growth. To determine if these adverse outcomes can be mitigated with dietary changes made after delivery, obese Sprague-Dawley rats (who had previously been fed a high-fat diet [AIN-93M, modified to contain 35% fat, w/w]) were assigned at parturition to continue to be fed this diet (HF) or switched to free access to a corresponding low-fat (LF) diet (AIN-93M, 4% fat w/w) or switched to the LF diet and restricted to consuming only 75% of ad libitum intake (LF/R). Dams lost weight during lactation, but weight loss was much less in the LF group (19g) than in the other two groups (47 and 59g, HF and LF/R, respectively). There was no appreciable change in body water; body fat decreased by about half in all groups, but most substantially in the LF/R group. Compared with the HF group, milk production was 50% higher in the LF group and 12% lower in the LF/R group. Milk lipid concentration tended to be higher and milk water concentration lower in the HF compared with the other two groups. Growth of the litters of the LF dams was significantly higher than both HF and LF/R dams. These results indicate that switching to a low-fat diet mitigates the negative effects of obesity and continued high-fat feeding on lactational performance and pup growth. Consumption of restricted quantities of a low-fat diet negatively affected milk production and failed to improve pup growth, despite the dams' mobilization of body fat in support of lactation.

The "fetal origins" hypothesis: challenges and opportunities for maternal and child nutrition

The "fetal origins" hypothesis postulates that conditions, most likely nutritional, "program" the fetus for the development of chronic diseases in adulthood. Associations between the newborn's size at birth and various determinants or consequences of chronic diseases have been identified in many, but not all, of the available studies. It remains to be established whether these associations are causal. Remarkably little information is available on the specific role of maternal nutritional status. The role of birth weight remains difficult to interpret except as a proxy for events in intrauterine life. Unfortunately, birth weight does not make an important contribution to the population attributable risk of cardiovascular disease; lifestyle factors during adulthood make much greater contributions. Data from experimental species suggest possible mechanisms for the origin of chronic disease early in life. It is too soon to use this research as a basis for new interventions directed at pregnant women for the purpose of reducing chronic disease in their offspring.

Obesity may impair lactogenesis II

Data from livestock species and experimental animal models suggest that excess body fatness may impair lactogenesis. For example, it has long been known that overfed dairy cows are at risk of fat cow syndrome, a condition characterized by lactation failure in the early postpartum period. Obese rats often lose their litters in the early postpartum period to primary lactation failure. A negative association between high body mass index (BMI) before conception and the duration of lactation has been documented in studies from diverse human populations. Findings from our laboratory establish that among women who ever attempted to breastfeed their infants, high BMI before conception was also associated with failure to initiate breastfeeding successfully. In a more recent study, we found that high prepregnant BMI was specifically associated with later onset of lactogenesis II. This was mediated by parity but not by breastfeeding behavior. Psychosocial factors related to a woman's intention to breastfeed and her planned duration of breastfeeding did not modify this association. Taken together, these findings in animals and women strongly suggest that maternal obesity in the perinatal period is a cause of delayed lactogenesis.

Impact of lactation on maternal body weight and body composition

Women worldwide generally lose weight and body fat during lactation. This loss, although increased by longer, more intensive breastfeeding, is modest and may be reduced by increased food intake and decreased activity. Higher parity and older age are associated with greater weight loss postpartum among poorly nourished women. Well-nourished women or those who breastfeed only for a limited time may not return to their prepregnant weight or body composition by the end of the lactation period. Those who are overweight or obese may have difficulty initiating or maintaining lactation. For the majority of women in the world, lactation is unlikely to represent a threat to their health. To advise women on how to optimize their health and lactational performance, one must consider all of the changes in maternal nutritional status that occur during a reproductive cycle, which may or may not compensate for the modest decreases in body weight associated with lactation.

Impact of food supplementation during lactation on infant breast-milk intake and on the proportion of infants exclusively breast-fed

To evaluate whether milk production can be improved by increasing food intake, a randomized, double-blind, supplementation trial was completed among 102 lactating Guatemalan women. The subjects were undernourished, as indicated by their low values for calf circumference (CC) and the small size of their infants at birth. A high-energy (2.14 MJ/d, HES) and a low-energy (0.50 MJ/d, LES) supplement were distributed 6 d/wk from wk 5 to 25 of lactation. Data were evaluated using repeated-measures analysis of variance on the increments from initial values for each outcome variable with one-tailed tests of statistical significance. The maternal energy intake increased 1.18 MJ/d (P < 0.01) more among the HES than the LES women. Benefit from supplementation was more evident among the more undernourished (CC </= median value, 29.5 cm) women. Among these 53 lower-CC women, infant milk and milk energy intakes were 10% higher (64 g/d and 14 MJ/d, respectively, at wk 25) in the HES than the LES group. After controlling for other determinants of infant milk and energy intakes in regression analyses, the significance of these differences increased to P < 0.04. However, there was no detectable effect on infant growth. Logistic regression analysis was used to show that HES women were significantly (P < 0.05) more likely than LES women to be exclusively breast-feeding their infants at wk 20, the time when the effect of supplementation was most evident. These findings establish that milk production and the duration of exclusive breast-feeding of undernourished women can be improved with the provision of supplemental food.

Linking maternal and infant benefits of a nutritional supplement during pregnancy and lactation

To evaluate the effect of a nutritional supplement on change in women's weight during a reproductive cycle and on the difference in birth weight between one infant and the previous one, we analyzed data on 176 complete reproductive cycles from an experiment that was conducted in rural Guatemala. Women with an initial weight <50 kg were classified as marginally nourished or malnourished. Women whose intake of the supplement was in the top 2 tertiles were distinguished from those whose intake was in the lowest tertile. Linear regression modeling was used to estimate the effect of supplementation on these outcomes and to control for confounding factors. Malnourished women gained weight during the reproductive cycle, but their second (study) infant tended to weigh less at birth than their prior-born infant. Higher intakes of supplement were associated with a less negative difference in birth weight. Marginally nourished women lost weight during the reproductive cycle and their second (study) infant tended to weigh more at birth than their prior-born infant. Higher intakes of supplement were associated with a less negative weight [corrected] trend for the women themselves. Well-nourished women and their infants did not show any of these benefits from supplementation. These findings help explain past contradictory findings on maternal depletion as well as on the benefits of nutritional supplementation for mothers and their infants.

Recognizing the reversible nature of child-feeding decisions: breastfeeding, weaning, and relactation patterns in a shanty town community of Lima, Peru

Researchers have normally considered weaning to be a non-reversible event. To determine the validity of this assumption, we interviewed 36 mothers of toddlers who were living in a poor shanty town of Lima, Peru. Data from 32 women were complete and used in this analysis. Mothers described their beliefs, practices, and decisions about breastfeeding, weaning, and relactation (the reintroduction of breastfeeding after weaning). We recorded attempted weaning events if the mother reported (1) purposefully not breastfeeding with the intention to wean, or (2) carrying out an action that was believed to cause the child to stop breastfeeding. Using a constant comparative approach, references to child-feeding decisions were coded, categorized, and analyzed. All mothers breastfed for at least 12 months; the median duration of breastfeeding was 25 months. There were several different patterns of child-feeding. Thirteen women never attempted to wean their children or had weaned on the first attempt. The majority (n = 19) of women, however, attempted to wean their children - some as early as 3 months of age but relactated between less than 1 day and 3 months later. Factors that influenced feeding decisions were primarily related to maternal and child health, and maternal time commitments. Children were weaned when there was a perceived problem of maternal health or time commitments and child health was not at risk of deterioration. Mothers postponed weaning because of poor child health. The primary reason for relactation was a child's negative reaction to weaning (e.g., incessant crying or refusal to eat). Personalities of the mother and child were important determinants of feeding decisions. These results demonstrate that maternal and child factors jointly influence child-feeding decisions and that these decisions are easily reversed. As relactation is culturally acceptable, health practitioners should consider recommending relactation when children have been prematurely weaned and human milk would improve their nutritional and health status.

Effects of under- and overnutrition on lactation in laboratory rats

To study the effects of maternal nutritional status on lactational performance, the diets of laboratory rats were manipulated with food restriction or increases in fat concentration. Compared with rats fed control diets ad libitum, conception rate, milk production and litter growth decreased and milk fat concentration increased in both chronically food restricted and obese animals. Chronically food restricted rats mobilized body fat and reduced their energy expenditure for maintenance and activity. Differences in suckling pattern between control and food-restricted rats affected hormone concentrations important for successful lactation. Obese rats experienced greater difficulty than controls in delivering their pups and more of their pups died in the first days of life. Milk production among obese rats may be constrained by poor appetite and the high heat production that characterizes lactation in litter-bearing species. There are many parallels as well as important differences between results obtained from these models and findings in nursing women. Nevertheless, these models provide useful information about the possible mechanisms by which maternal nutritional status affects lactational performance.

[A combined methodology for understanding the duration of breast feeding the poor neighborhoods of Managua, Nicaragua]

This study examined the relationship of several maternal variables to the duration of exclusive breast-feeding and the total duration of breast-feeding, along with attitudes, perceptions, and beliefs about breast-feeding among women living in poor neighborhoods of Managua, Nicaragua. The field work was carried out in December 1992 and January 1993 using qualitative and quantitative methods. A structured questionnaire was administered in interviews with 556 mothers of children under 12 months of age, and meetings of four directed discussion groups were held, in which a total of 20 women participated. At one week of age, almost all the children of the mothers who were surveyed had been breast-fed, but only 45% had been exclusively breast-fed. At 12 weeks old, 30% were already completely weaned. The discussion groups revealed the coexistence of positive opinions about both breast-feeding and bottle-feeding. However, exclusive breast-feeding was considered harmful for the mother, and breast milk was not thought to be sufficient nourishment for the child. Previous experience was strongly related to the duration of exclusive breast-feeding and to total breast-feeding duration. Attitudes, social support, and work situation were important factors influencing the total length of time women breast-fed a child. In general, the results obtained through the interviews and in the discussion groups were in agreement and showed that the elements needed to promote exclusive breast-feeding were social support, a favorable community environment, and policies that dealt with problems faced by working mothers. The complementary research methods were useful for obtaining information about the relative importance of different factors that determine the duration of breast-feeding and for understanding that practice in greater depth from the mother's point of view.

Maternal obesity and breast-feeding success in a rural population of white women

Maternal obesity interferes with the initiation and maintenance of lactation in animal models but it has not been investigated widely in women. We reviewed medical records from a white population to examine the relation between prepregnant overweight [body mass index (BMI; in kg/m2) 26.1-29.0] and obesity (BMI > 29.0) on initiation and duration of breast-feeding. Logistic regression revealed that of those who ever put their infants to the breast (n = 810), women who were overweight [odds ratio (OR) = 2.54, P < 0.05] or obese (OR = 3.65, P < 0.0008) had less success initiating breast-feeding than did their normal-weight counterparts (BMI < 26.1). Proportional-hazards regression revealed higher rates of discontinuation of exclusive breast-feeding in overweight (RR = 1.42, P < 0.04) and obese (RR = 1.43, P < 0.02) women and higher discontinuation of breast-feeding to any extent in overweight (RR = 1.68, P < 0.006) and obese (RR = 1.73, P = 0.001) women. Controlling for parity, socioeconomic status, maternal education, and other factors that often covary with maternal obesity and breast-feeding did not change these results. These results suggest that excessive fatness in the reproductive period may inhibit lactational performance in women.

Breast milk or animal-product foods improve linear growth of Peruvian toddlers consuming marginal diets

Although breast-feeding is widely accepted as important for infant health, its benefits during the second year of life have been questioned. We analyzed data from 107 breast-fed and weaned Peruvian children living in a periurban community to determine whether breast milk contributed to improved linear growth between 12 and 15 mo of age. Breast-feeding frequency was self-reported; intakes of complementary foods and animal products were estimated from a food-frequency survey. Multivariate-linear-regression analysis was used to predict the length of the children at 15 mo of age. Determinants of length included length and weight-for-length at 12 mo of age (US National Center for Health Statistics standards), interval between 12- and 15-mo measurements, breast-feeding frequency, incidence of diarrhea, and intakes of complementary and animal-product foods. Complementary foods, animal-product foods, and breast milk all promoted toddlers' linear growth. In subjects with low intakes of animal-product foods, breast-feeding was positively associated (P < 0.05) with linear growth. There was a 0.5-cm/3 mo difference in linear growth between weaned toddlers and children who consumed the average number of feedings of breast milk. Linear growth was also positively associated with intake of animal-product foods in children with low intakes of complementary foods. The negative association between diarrhea and linear growth did not occur in subjects with high complementary-food intakes. When the family's diet is low in quality, breast milk is an especially important source of energy, protein, and accompanying micronutrients in young children. Thus, continued breast-feeding after 1 y of age, in conjunction with feeding of complementary foods, should be encouraged in toddlers living in poor circumstances.

Duration of breastfeeding associated with obesity during adolescence

The relationship between duration of breastfeeding and obesity (body mass index > or = 85 percentile) at adolescence was investigated in a white, rural population (n = 136) in which confounding by race was absent and confounding by socioeconomic status was expected to be minimal. Relevant data were abstracted from hospital charts. When examined independently, minimal (< or = 2 months) or no breastfeeding was positively associated with adolescent obesity (p < 0.03). This association was present in the lower but not the higher socioeconomic status group. However, when sex, birthweight, and socioeconomic status were included in a multiple regression model, duration of breastfeeding was no longer significantly associated with obesity during adolescence.

Food supplementation during lactation shortens anestrus and elevates gonadotropins in rats

Breastfeeding delays the resumption of ovulation in women, a phenomenon particularly important in less developed areas. Although human and animal studies indicate that undernutrition extends the period of lactational anestrus, the effect of improving nutritional status during lactation on this time of infecundability, however, is less clear. To assess the effects of food supplementation on duration of lactational anestrus, Sprague-Dawley rats were assigned to one of three dietary groups: 1) control (C), given unrestricted access to diet AIN-76A; 2) food-restricted (FR), fed 50% of the control intake; and 3) food-supplemented (FS), food-restricted until d 0 of lactation and thereafter given unrestricted access to diet AIN-76A. Time to first detectable proestrus was monitored starting on d 10 of lactation. Nursing behaviors and gonadotropin and prolactin concentrations were measured in both intact and ovariectomized dams on d 10, 15 and 20 of lactation; we report these data only on the ovariectomized group, which represents the more appropriate animal model of human reproductive physiology during lactation. Proestrus returned significantly (P < 0.0001) sooner in both FS (18.1 +/- 2.4 d) and C (18.0 +/- 2.9 d) than in FR (28.8 +/- 2.8 d) intact dams. FS rats had higher luteinizing hormone and follicle stimulating hormone concentrations than FR rats (P < 0.0001 for each). Prolactin concentrations were lower on d 20 than on d 10 of lactation for all groups (P < 0.02), but we found no effect of dietary treatment. FS rats spent more time away from their pups (P < 0.05) and experienced less suckling (P < 0.05) than FR rats on d 15 of lactation. These results indicate that food supplementation of previously underfed rats hastens the return of ovulation and is accompanied by alterations in nursing behaviors.

Association of breastfeeding and stunting in Peruvian toddlers: an example of reverse causality

BACKGROUND

Child feeding recommendations include breastfeeding beyond 12 months, however, some researchers have reported increased rates of malnutrition in breastfed toddlers. A negative association between growth and breast-feeding may reflect reverse causality; that is, the outcome (growth) is a determinant of the predictor (breastfeeding), and not vice versa. We examined this question with data from 134 Peruvian toddlers.

METHODS

A linear regression analysis predicted length at the age of 15 months by length at 12 months, study interval, and 12-14.9-month breastfeeding, complementary food intake, and diarrhoeal incidence. This analysis defined the association between breastfeeding and linear growth. To elucidate the direction of the effect between breastfeeding and linear growth, logistic regression was used to predict the probability of weaning by the end of 14 months. Determinants included weight-for-age (W/A) at 12 months, complementary food intake at 9-11.9 months, and change in diarrhoeal incidence between 9 and 14.9 months.

RESULTS

There was a significant (P < 0.01) interaction of breastfeeding, diarrhoeal incidence, and complementary food intake on length at 15 months. Increased breastfeeding was associated with a 1.0 cm decrease in length gain when dietary intake was low and diarrhoeal morbidity was high, implying that breastfeeding is harmful. The logistic analysis, however, demonstrated that the risk of weaning decreased only when W/A and dietary intake were low and diarrhoeal morbidity was high.

CONCLUSIONS

The negative association between breastfeeding and linear growth reflected reverse causality. Increased breastfeeding did not lead to poor growth; children's poor growth and health led to increased breastfeeding. Children's health must be considered when evaluating the association of breastfeeding with anthropometric outcomes.

Documentation of second-by-second breastfeeding behaviors using a novel method

The specific way nursing patterns influence the duration of postpartum amenorrhea is unknown. This may result from the shortcomings of available methods: the daily log and recall. We tested these against a novel method, an event monitor (EM), consisting of a wrist-worn stopwatch that stores events. Exclusively breastfeeding women (n = 11) were assigned randomly to use each of the three methods twice during a 2-week period surrounding Weeks 4, 8, and 12 postpartum. More nursing episodes were recorded with the EM than log during Week 4 (p < 0.03) and Week 8 (p < 0.02). EM captured more episodes than recall during all study periods (p < 0.004). The EM was considered as acceptable and accurate to mothers as the other methods and, therefore, is a useful option for documenting breastfeeding patterns.

Consumption of a high fat diet impairs reproductive performance in Sprague-Dawley rats

Rats made obese by cafeteria feeding have poor reproductive outcomes. To investigate this phenomenon in animals fed a more nutritionally adequate diet, female rats were fed either a high fat (HF) (modified AIN-76A, 35 g fat/100 g diet) or a control (C) (AIN-76A, 5 g fat/100 g diet), diet, beginning at 27 d of age. To assess reproductive performance, rats were studied at d 0, 5 and 18 of pregnancy and on d 3 of lactation. Pregnancy rates were significantly (P < 0.001) lower in the high fat-fed rats than in the control-fed rats (56.4 and 89.1%, respectively). There was no difference between groups in total pregnancy weight gain or the proportion of weight gained during pregnancy that was retained by the dam. High fat-fed dams tended to gain weight more rapidly early in gestation than control-fed dams and then less rapidly than control-fed dams during the last week of gestation. Litter number and pup weight at birth did not differ between groups, but of high fat-fed pups had significantly higher (P < 0.04) mortality rates than pups of control-fed dams (16.5 and 7.7%, respectively) over the first 3 d of life. Control-fed dams experienced the expected reduction (P < 0.05) in plasma insulin concentrations between the end of pregnancy and early lactation, but high fat-fed dams did not. Thus, physiological mechanisms controlling distribution of metabolic fuels may not be functioning properly in high fat-fed dams. Therefore, consuming a high fat diet reduces a rat's capacity to conceive and ability to maintain her litter during the perinatal period.

Adherence to iron supplementation during pregnancy in Tanzania: determinants and hematologic consequences

Limited adherence to iron supplementation is thought to be a major reason for the low effectiveness of anemia-prevention programs. In rural Tanzania, women at 21-26 wk of gestation were randomly given either 120 mg of a conventional (Con) iron supplement or 50 mg of a gastric-delivery-system (GDS) iron supplement for 12 wk. Adherence was assessed by using a pill bottle equipped with an electronic counting device. Adherence in the GDS group was 61% compared with 42% for the Con group. In both groups, women experiencing side effects had about one-third lower adherence. Fewer side effects were observed in the GDS group. In a subgroup of women with a low initial hemoglobin concentration (< or = 120 g/L), the response to the iron supplements suggested that both of the applied doses were unnecessarily high for adequate hematologic response in a population with a marginal hemoglobin concentration. The GDS group appeared to require a dose one-fourth as high as that of the Con group for an equal effect on improving hemoglobin to normal concentrations.

Naloxone administration does not relieve the inhibition of gonadotropin release in food-restricted, lactating rats

Lactational anovulation is an important factor in determining birth spacing in women living in developing countries. Therefore, a more comprehensive understanding of the mechanisms involved in the relationships among lactation, nutrition and ovulation is important. This study was designed using the food-restricted, lactating rat to examine whether endogenous opioids might be involved in depressing gonadotropin release. Females were mated after 65 d of age and, beginning on d 42 of life, offered food in unrestricted amounts (control) or were food restricted to 50% of what the controls consumed. On d 15 of lactation, dams were injected with either naloxone hydrochloride (3 mg/kg body weight) or saline and killed 0, 15, 30 or 60 min later. Plasma was analyzed for luteinizing hormone, follicle-stimulating hormone and prolactin. Food restriction decreased plasma concentrations of luteinizing hormone and follicle-stimulating hormone (P < 0.005). Naloxone administration marginally influenced follicle stimulating hormone (P < 0.1), but not luteinizing hormone concentration regardless of diet group. The interaction among diet group, drug group and time of killing was significant for plasma prolactin concentration (P < 0.05). Food restriction lowered prolactin concentrations, but this effect was diminished with increasing time after injection of naloxone. Furthermore, the magnitude of the effect of food restriction was lessened and even reversed with treatment of naloxone. These results indicate that endogenous opioids are not the primary mechanism suppressing luteinizing hormone release in food-restricted lactating rats.

Screening for nutrition interventions: the risk or the differential-benefit approach?

The risk approach has been promoted to improve screening for nutrition interventions on the premise that indicators of risk also predict greater response to interventions. This study tested whether the determinants of the risk of poor growth (eg, low length-for-age) at 36 mo of age were the same as the determinants of differential benefit from food supplementation. The sample included 460 Guatemalan children who were exposed to either a high-energy, high-protein drink (atole) or a low-energy, no-protein drink (fresco) during their first 36 mo of life [INCAP (Institute of Nutrition of Central America and Panama) supplementation trial]. Low maternal stature, poor socioeconomic status, inadequate home diet, high diarrhea rates, and low anthropometry scores at 3 or 6 mo were all determinants of the risk of poor growth. Only indicators of child's thinness at 3 or 6 mo of age (low weight-for-age, weight-for-length, or midupper arm circumference) were determinants of differential benefit from supplementation. Thus, the development of screening indicators should be based on analyses of the predictors of differential benefit, not on conventional risk-factor analysis.

Food restriction, gonadotropins, and behavior in the lactating rat

This study sought to quantify effects of undernutrition on behaviors and to relate these to gonadotropin and prolactin concentrations in the lactating dam. Dams were studied in a 2 x 3 factorial design with litter size and food intake as the two factors. Behavioral data were collected from each dam and her litter on day 9, day 14, and day 19 of lactation, and maternal blood samples collected. Plasma was analyzed for luteinizing hormone, follicle stimulating hormone and prolactin. On day 15 of lactation, percent time nursing, number of pups actively nursing, total number of pups nursing and dam location acted as mediating factors of the effect of diet group on plasma luteinizing hormone concentration. No such relationships were seen for plasma follicle stimulating hormone, and only nest condition score appeared to be a mediator for plasma prolactin concentration. In conclusion, this analysis suggests that food restriction indirectly influences plasma concentration of luteinizing hormone, but not follicle stimulating hormone, by changing maternal and pup behaviors. The relationship among diet, behavior and circulating prolactin was less clear.

Pre- and postweaning food restrictions interact to determine reproductive success and milk volume in rats

This study was designed to determine if nutrient availability during gestation and early life modifies the effects of subsequent dietary intake on reproductive and lactation performance. Rat pups, whose mothers had been allowed free access to food or were food-restricted to 50% of ad libitum consumption were assigned to free access or food restricted groups after weaning, creating 4 groups (pre- and postweaning diet). Pre- and postweaning diets interacted significantly to influence age at conception, number of pups born, and milk yield on d 14 of lactation. Early undernutrition deterred conception in dams later allowed free access to food and resulted in fewer pups born to dams later allowed free access to food, but not those in the food-restricted group. By d 15 of lactation, only dietary treatment after weaning influenced litter weight. Milk yield per gram dam weight was not impaired in the food restricted-ad libitum group but was lowered in dams in the ad libitum-food restricted group. Milk yield per gram litter weight was not impaired in ad libitum-food restricted dams but was reduced in food restricted-ad libitum dams. These results extend to the preweaning period our previous finding that past or current food restriction impairs reproductive success and decreases milk yield in rats.

Nutritional status and behavior during lactation

Effects of chronic maternal food restriction and time of day on maternal and pup behaviors were examined in ovariectomized Sprague-Dawley rats (n = 26). Dams were fed ad lib (AL) or were restricted to 85% (85 AL) or 70% (70 AL) of ad lib intake. Dams and their 5-pup litters were observed for 45 min at night on days 9, 14, and 19 of lactation and during the day on day 14. A novel behavioral instrument was used to observe maternal and pup behaviors. At night, food-restricted animals engaged in more nursing behaviors than AL animals. Differential pup stimuli may account for this difference. AL animals engaged in more nursing behaviors during the day than night, whereas 70 AL animals demonstrated the opposite diurnal pattern. Time of feeding may explain this difference. On the other hand, 85 AL animals behaved similarly during the day and at night. Therefore, alterations in circadian behavior patterns are less pronounced in rats mildly restricted (85 AL) than in rats more food restricted (70 AL).

Evaluation of indicators for use in vitamin A intervention trials targeted at women

This paper examines the ability of three indicators to detect changes in women's vitamin A status. Serum retinol concentration, milk vitamin A concentration, and milk vitamin A per gram milk fat were used to assess the vitamin A status of mildly deficient Indonesian women before and after supplementation in a randomized intervention trial. Choice of indicator made a fourfold difference in the sample size required to measure a statistically significant change in vitamin A status. Milk vitamin A per gram milk fat was the best indicator of response, milk vitamin A concentration was intermediate, and serum retinol concentration performed most poorly. Serum retinol concentration was equally responsive across the range of vitamin A status in this population. The milk indicators were more responsive among women of lower status than women of higher status. Milk vitamin A is an efficient indicator for monitoring the effects of vitamin A interventions in women.

Effects of maternal nutritional status and maternal energy supplementation on length of postpartum amenorrhea among Guatemalan women

To investigate the extent to which better maternal nutrition leads to reduction in length of postpartum amenorrhea, multivariate-logistic and linear-regression analyses were applied to data on 339 mother-infant pairs from the longitudinal Guatemalan Four Village Study, 1969-1977. Maternal triceps skinfold thickness was negatively associated with length of amenorrhea when infant supplementation (a proxy for reduced suckling) was accounted for. However, its effect was small: amenorrhea was only 0.5 mo shorter among women at the 75th percentile than among those at the 25th, equivalent to less than even one additional child during the women's reproductive years. Maternal supplementation was not associated with length of amenorrhea when infant supplementation was controlled. This is in contrast to previous studies in which breast-feeding or infant supplementation was not controlled. These results suggest that infant, not maternal, supplementation influences length of postpartum amenorrhea, and that maternal nutritional status has minimal influence.