Obesity influences transitional states of disability in older adults with knee pain

Rejeski WJ, Ip EH, Marsh AP, Zhang Q, Miller ME. Obesity influences transitional states of disability in older adults with knee pain.

Objectives

This study employed relatively new statistical methods to understand how many states are needed to describe disability in older adults with knee pain, describe the relative probability of transitioning between states over time, and examine whether obesity influences the probability of transitioning between states.

Design

Prospective epidemiologic study of older adults with knee pain.

Setting

Community.

Participants

The participants, 245 women and 235 men, were 65 years or older, had chronic knee pain on most days, and had difficulty with at least 1 mobility-related activity caused by knee pain.

Interventions

Not applicable.

Main Outcome Measure

The primary instrument, the Pepper Assessment Tool for Disability, evaluated self-reported difficulty with mobility, basic activities of daily living (ADLs), and instrumental activities of daily living (IADLs).

Results

The Hidden Markov Model yielded 6 states reflecting changes in mobility, ADLs, and IADLs. There is evidence that loss in more demanding mobility-related activities such as stair climbing is an early sign for the onset of disability and that functional deficits in the lower extremities are critical to the early loss of ADLs. Overall the trend is for older adults to experience greater progression than regression and for obesity to be important in understanding severe states of disability.

Conclusions

These data provide a strong rationale for characterizing disability on a continuum and underscore the fluid nature of disability in older adults. As expected, lower-extremity function plays a key role in the disablement process; obesity is also particularly relevant to understanding severe states of disability.     

Upper-arm anthropometry: an alternative indicator of nutritional health to body mass index in unilateral lower-extremity amputees?

Miller M, Wong WK, Wu J, Cavenett S, Daniels L, Crotty M. Upper-arm anthropometry: an alternative indicator of nutritional health to body mass index in unilateral lower-extremity amputees?

Objective

To evaluate the utility of body mass index (BMI) and corrected-arm-muscle area (CAMA) as measures of nutritional health for lower-limb amputees attending prosthetics clinics.

Design

Cross-sectional study.

Setting

Prosthetics clinic in Australia.

Participants

Unilateral lower-extremity amputees (N=58; age range, 21-91y; 37 transtibial, 21 transfemoral) attending a regional prosthetics clinic between May and November 2003.

Interventions

Not applicable.

Main Outcome Measures

Weight (without prosthesis), corrected and uncorrected for the amputated limb was used with height estimated from knee height to calculate corrected BMI (cBMI) and uncorrected BMI (uBMI). CAMA was calculated using the mean of triplicate mid-upper-arm circumference (MUAC) and triceps skinfold thickness (TST) measurements. The Mini Nutritional Assessment (MNA) and Assessment of Quality of Life were administered according to recommended protocols. The Pearson correlation was used to determine the strength and significance of associations between variables, and bivariate regression analyses were performed to determine whether an association existed between the nutritional variables (BMI, CAMA, MNA) and quality of life (QOL).

Results

There were no statistically significant differences in the measures of nutritional health according to site (transtibial, transfemoral) of amputation. MUAC, TST, and CAMA all showed moderate to high positive correlations (r range, .541−.782) with both cBMI and uBMI. The strength of the relationship between the MNA and cBMI/uBMI was weaker (r=.383, r=.380, respectively) but remained positive and statistically significant (P=.003). QOL was not associated with cBMI or uBMI but was related to CAMA (β=−.132; P=.030) and MNA (β=−.561; P=.017).

Conclusions

For persons with unilateral lower-extremity amputation, measurement of upper-arm anthropometry may be a more useful indicator of nutritional health and its consequences than BMI.     

Smokers' beliefs about the inability to stop smoking

We recruited 367 current daily smokers via the Internet and randomized them to rate the causes of an inability to stop smoking, inability to stop problem alcohol use, or inability to lose excess weight in a fictional scenarios. Most smokers attributed inability to stop smoking to addiction (88%), habit (88%) and stress (62%). Surprisingly, equal numbers of smokers agreed and disagreed that inability to stop smoking was due to lack of willpower or motivation. Most disagreed that it was due to biological factors, denial, family/upbringing, genetics, mental disease, personality problem, psychological problems, or weakness of character. Many expected correlations among perceived causes were not found; e.g. endorsement of addiction was not inversely related to endorsement of willpower. Most smokers endorsed treatment. Higher ratings of addiction were related to endorsing treatment, and higher ratings of motivation were related to endorsing no need for treatment; however, these relationships were of small magnitude. Ratings of almost all the causes varied across the three problems; e.g. ratings of addiction were greater for smoking than for problem alcohol use. In summary, smokers appear to view the inability to stop smoking as multicausal; however, their views of causes are only weakly related to attitudes towards treatment. Given the several unexpected findings, qualitative research into smokers' conceptualizations about smokers' inability to stop smoking is indicated.     

湖北省中老年居民体质指数的动态变化研究

目的观察体质指数的动态变化,为卫生研究和政策制订提供依据。方法采用分层多阶段整群随机抽样的方法对抽取的观察户连续观察测量。结果1991～2006年BMI小于18.5的百分率呈下降趋势,1991年为13.6%,2006年为4.7%。超重和肥胖的百分率呈增加的趋势,超重从1991年的18.0%增加到2006年的28.0%,平均每年增加0.7;肥胖则从从1991年的7.4%增加到2006年的11.7%,平均每年增加了0.3。2006年BMI〈18.5的百分率由高到低依次为农村、郊区、城市和县城,分别为为6.7%、3.5%、2.8%和2.4%;超重百分率由高到低依次为城市、郊区、县城和农村,分别为35.9%、33.7%、27.7%和22.6%,肥胖百分率由高到低依次为城市、县城、郊区和农村,分别为18.9%、16.9%、12.8%和6.3%。结论提示过去15年间,湖北省城乡居民的营养不良率大幅度下降,尤其是郊区和农村,但农村BMI〈18.5的百分率仍相对较高。超重肥胖率较高,增加较快,应列为重大公共卫生问题之一,认真研究对待。     

Prevention and treatment of type 2 diabetes: current role of lifestyle, natural product, and pharmacological interventions

Common complications of type 2 diabetes (T2D) are eye, kidney and nerve diseases, as well as an increased risk for the development of cardiovascular disease and cancer. The overwhelming influence of these conditions contributes to a decreased quality of life and life span, as well as significant economic consequences. Although obesity once served as a surrogate marker for the risk of T2D, we know now that excess adipose tissue secretes inflammatory cytokines that left unchecked, accelerate the progression to insulin resistance and T2D. In addition, excess alcohol consumption may also increase the risk of T2D. From a therapeutic standpoint, lifestyle interventions such as dietary modification and/or exercise training have been shown to improve glucose homeostasis but may not normalize the disease process unless weight loss is achieved and increased physical activity patterns are established. Furthermore, utilization of natural products may serve as a significant adjunct in the fight against insulin resistance but further research is needed to ascertain their validity. Since it is clear that pharmaceutical therapy plays a significant role in the treatment of insulin resistance, this review will also discuss some of the newly developed pharmaceutical therapies that may work in conjunction with lifestyle interventions, and lessen the burden of behavioral change as the only strategy against the development of T2D.     

Ghrelin is a physiological regulator of insulin release in pancreatic islets and glucose homeostasis

Ghrelin, an acylated 28-amino acid peptide, was isolated from the stomach as the endogenous ligand for the growth hormone (GH) secretagogue receptor (GHS-R). Circulating ghrelin is produced predominantly in the oxyntic mucosa of stomach. Ghrelin potently stimulates GH release and feeding, and exhibits positive cardiovascular effects, suggesting a possible clinical application. Low plasma ghrelin levels are associated with elevated fasting insulin levels and insulin resistance, suggesting both physiological and pathophysiological roles for ghrelin in glucose metabolism. Here, we review the physiological role of ghrelin in the regulation of insulin release and glucose metabolism, and a potential therapeutic avenue to treat type 2 diabetes by manipulating ghrelin and/or its signaling. Ghrelin inhibits insulin release in mice, rats and humans. The signal transduction mechanisms of ghrelin in islet β-cells are distinct from those utilized in GH-releasing and/or GHS-R-expressing cells. Ghrelin is expressed in pancreatic islets and released into pancreatic microcirculations. Pharmacological and genetic blockades of islet-derived ghrelin markedly augment glucose-induced insulin release in vitro. In high-fat diet-induced mildly obese mice, ghrelin-deficiency enhances insulin release and prevents impaired glucose tolerance. Thus, manipulation of insulinostatic function of ghrelin — GHS-R system, particularly that in islets, could optimize the amount of insulin release to meet the systemic demand, providing a potential therapeutic application to prevent type 2 diabetes.     

Promoting physical activity and healthy eating: Convergence in framing the role of industry

This commentary addresses a little explored aspect of prevention, namely, how public health practitioners conceptualize the roles of industries whose business interests may be at odds with physical activity and eating nutrient-rich foods. Taking their cues from successful campaigns in tobacco control, many public health advocates have framed obesity as a battle with the food industry. Such framing presents problems when it exacerbates existing tensions between practitioners in nutrition and physical activity, and alienates potential fitness industry partners. Creating healthy environments requires reframing expectations of all industries that influence physical activity and inactivity. A broader view of the influence of corporate practices on physical and social environments will help both physical activity and nutrition advocates identify what they can do together, and in partnership with the business sector, to create environments that promote activity and nutritious eating.     

Inducing impulsivity leads high and low restrained eaters into overeating, whereas current dieters stick to their diet

Previous research has related impulsivity to overeating and obesity. However, the precise nature of this relation has not been examined yet. One possibility is that impulsivity causes overeating and hence contributes to overweight. To test this possibility we induced impulsivity versus inhibition to see whether this would affect food intake. In the first study participants were cognitively primed with the concepts “impulsivity” or “inhibition”. Caloric intake was significantly higher in the Impulsivity Condition compared to the Inhibition Condition. This effect was even stronger for highly restrained participants. In the second study impulsivity was manipulated via behavioural instructions. Restrained and unrestrained nondieters acted as expected: their caloric intake was significantly higher when impulsivity was induced compared to inhibition. Current dieters sharply reduced their caloric intake following the impulsivity induction. These results are in accordance with Lowe's model that, contrary to restraint theory, states that restraint and current dieting are different constructs that affect eating regulation differently. At least for nondieters it can be concluded that heightened impulsivity versus inhibition leads to a higher food intake in the lab.     

儿童青少年肥胖与神经肽Y第二受体基因多态性

目的 探讨儿童青少年肥胖与神经肽Y第二受体(NPY2R)基因rs1047214多态性的相关性,及其与代谢综合征的关系.方法 选择北京市2030名7～18岁的中小学生进行身体测量、血液生化指标测定和rs1047214多态性检测.结果 NPY2R基因rs1047214多态性的等位基因突变率(T>C)为18.6%;非肥胖组的纯合突变CC基因型频率为3.7%.明显高于肥胖组(1.7%,P<0.05);不同基因型BMI、腰围、腰臀比和腰围身高比水平的差异有统计学意义(P<0.05),CC基因型低于非纯合突变型,性别分析显示男性差异有统计学意义;但是,采用多元线性回归分析方法,用BMI调整后,不同基因型腰围、腰臀比和腰围身高比水平的差异无统计学意义(P>0.05);不同基因型的血脂、血压、血糖指标水平的差异无统计学意义.结论 儿童青少年NPY2R基因rs1047214多态性的突变率与男性肥胖有关,但与血脂、血压、血糖异常可能没有显著关联.     

不同代谢综合征定义在肥胖儿童中应用比较

目的 比较2007年国际糖尿病联盟(IDF)、Cook等和Silva等提出的代谢综合征(MS)定义在肥胖儿童中的应用情况,及中国、美国切点对其影响,以提出适应中国肥胖儿童特点的MS定义.方法 采用回顾性方法,收集2004年1月至2008年12月在仁济医院临床营养科肥胖病专科门诊就诊7～18岁肥胖儿童,排除患有遗传性代谢性疾病、严重肝脏及肾脏疾病、药物等因素导致的继发性肥胖、服用影响内分泌代谢药物的儿童和资料不全者.采集人体测量指标(身高、体重、腰围)、血压、血脂、空腹血糖以及空腹血胰岛素.胰岛素抵抗采用HOMA指数进行评估.在判断MS组分(中心性肥胖和高血压)时,分别采用中国切点和美国切点.采用Kappa一致性检验分析不同定义的吻合情况.结果 纳入研究136名儿童,男生103名,女生33名.采用美国切点的三种定义MS患病率依次为19.2%、34.6%、52.9%;采用中国切点的相对应定义MS患病率为19.2%、43.4%、58.1%,差异无统计学意义,两两之间Kappa值分别为1、0.79、0.90.Cook等、da Silva等定义两者Kappa值为0.52(D2/D3)/0.51(DS/D6),IDF定义与其他定义Kappa值为0.24～0.4.仅Cook等、da Silva等定义所诊断MS儿童的HOMA指数高于非MS儿童.结论 门诊肥胖儿童MS的患病率较高,且很大程度上取决于定义.在考虑胰岛素抵抗方面,Cook等、daSilva等提出的MS定义对门诊肥胖儿童可能更为适合.中国和美国切点对MS诊断无影响,均适合中国肥胖儿童.